International Bryozoology Association - 12th Conference, Dublin, 2001 - Abstracts

Analysis of bryozoan communities in the Weddell Sea, Antarctica.

Beate Bader
Institut für Geowissenschaften, Abt. Geologie, Universität Kiel
Olshausenstr. 40, 24118 Kiel, Germany

The main purpose of this project is the study of Antarctic bryozoan communities with regard to their distribution, density and structure. In contrast to their systematics, the role of bryozoans in the benthic ecosystem of the Antarctic shelf is largely unknown. During the RV «Polarstern» cruise from March to May 2000 bryozoans were collected from the Weddell Sea and the Antarctic Peninsula. First results show no clear spatial pattern for species richness on the shelf of the Weddell Sea. There is no bathymetric pattern in water depths of 200-800 m. In stations above 200 m water depth the bryozoan fauna is much poorer in species richness. Many of species can now be described for the first time for the Weddell Sea. All growth forms are present from encrusting sheets to flexible and rigid erect colonies. A high amount of erect species like Cellarinella and Melicerita are anchored by rootlets in the sediment. This seems to be a good adaptation to the fine grained sediment on the shelf. The absence of strong distribution patterns of bryozoan species can probably be related with current regimes and topography. Nearly all species show reproductive structures and many were observed to be fertile in autum. These bryozoan species breed over winter time and release the larvae in spring. Hence, contrary to the suggestion in literature, summer time is not the only reproductive season for most of the bryozoan species on the Antarctic shelf.

Modelling determinants of growth and mortality in Antarctic bryozoans.

David K. A. Barnes
Department of Zoology and Animal Ecology, University College Cork, Cork, Ireland

Sammy De Grave
The Oxford University Museum of Natural History, Parks Road, Oxford, UK

Bryozoans (or at least those species to have been measured to date) seem fairly typical amongst Antarctic benthos, in terms of both the timing and magnitude of growth. Growth varies interspecifically from nearly comparable to much slower than warm water equivalent species. Mortality, in shallow water at least, is very high. Various factors, including species identity, age, year, competition, substratum stability and locality have been suggested, by various studies, as being influential. We analysed 5000 colonies of three of the most abundant and ubiquitous cheilostomatid species in shallow water Antarctic assemblages, Celleporella bougainvillei, Fenestrulina rugula and Inversiula nutrix. Substratum size (surface area) and depth were treated as separate factors, but both act as proxies for substratum stability. Intra- and inter-specific competition were also treated as separate factors. Growth and mortality of each study species was scored as the number of zooids per year, because of the known high seasonal variability. The significance and contribution of each of the factors to both growth and mortality in each of the three species was determined and compared. The applicability of the results are discussed in relation to growth of polar faunas and processes governing growth in warmer water.

Seasonality and inter-annual variability in colonisation and recruitment patterns of temperate encrusting fauna.

David K. A. Barnes and Ben C. Maughan
Department of Zoology and Animal Ecology, University College Cork, Cork, Ireland

Sets of triplicate slate panels were immersed at two sites in SW Ireland and at three depths and analysed monthly between 1997 and 2001. The mean number of recruits varied on both seasonal and interannual timescales, peaking in summers and 1998 in particular. Relative sizes of recruitment peaks varied between sites and especially between depths. Recruitment on intertidal panels was an order of magnitude lower than on those in the subtidal, even when allowing for immersion period. The mean number of species followed a predictable seasonal pattern, peaking in summer, and varied little on an interannual basis. Per cent cover varied less predictably with season and year. Typically just two of three colonist species were responsible for 90% of space occupation, but this also varied with time on a variety of scales. The dominance of a few taxa was reflected in the diversity index values peaking during winter, when the influence of these species was minimal. Recruitment of individual taxa showed a variety of patterns both in terms of the timing of initiation or cessation and duration. These included predictable bursts of settlement of similar seasonal timing (e.g. Aetea sp. and) and predictable long duration bouts (e.g. Chorizopora brongniartii) to less predictable bursts (e.g. the sponge Scypha ciliatum) and dribbles (e.g. Scrupocellaria sp.). The variability of the study assemblages in both time and space illustrate the importance of within and between site replication and longer term data sets.

Use of radioactive labelled silt to show depletion of food supply by upstream colonies of Flustrellidra hispida.

M.A. Best and J.P. Thorpe
University of Liverpool, Port Erin Marine Laboratory, Port Erin, Isle of Man IM9 6JA, UK

Colonies of the large ctenostome bryozoan Flustrellidra hispida (Fabricius) were placed in a chamber with a slow flow through it and were offered a mixture of food. This consisted of a suspension of the single celled alga Tetraselmis suecica mixed with fine particles of clay silt, which had been allowed to acquire a bacterial coating. The bacteria had been previously labelled with radio isotope so that if they were eaten off the ingested silt particles, the colonies would show labelling. The colonies did take up the label and in several cases the upstream colonies showed much higher levels of radioactivity. If bacterial inhibitor was used during labelling, significantly reduced levels of label were found in the Bryozoa. It is concluded that the bryozoans are removing the bacteria from the silt and that the upstream colonies depleted the food supply to the downstream colonies.

Use of radioactive labelled food to assess the role of the funicular system in the transport of metabolites in the cheilostome Membranipora membranacea.

M.A. Best and J.P. Thorpe
University of Liverpool, Port Erin Marine Laboratory, Port Erin, Isle of Man IM9 6JA, UK

Colonies of the large cheilostome Membranipora membranacea (L.) were fed radioactive labelled algal cells in a follow up to the earlier study of Best and Thorpe (1985). It was intended to try to establish the path taken by labelled metabolites when transported across the colony. The earlier work had shown that transport occurs, but the levels of activity used had been too great to allow resolution of detail in autoradiographs. Here we used a range of lower levels in an attempt to increase resolution. At higher magnifications the autoradiographs were somewhat 'fuzzy', but the results supported the assumption that the funiculus transports metabolites between zooids in a colony.

A Lower Devonian bryozoan fauna in the Belgian Ardenne.

Françoise P. Bigey
Université P. & M. Curie, Laboratoire de Micropaléontologie, 75252 Paris Cédex 05, France

In the Hercynian part of the Belgian Ardenne Massif, crops out near by La Roche-en-Ardenne (upper Ourthe valley) a Lower Devonian Formation, so-called Villé Formation. It belongs to the southeastern border of the Dinant Basin as structural unit. The Villé Formation is characterized mostly by sandy or argillaceous limestones and calcareous shales. The biostratigraphy was established thanks to spiriferid brachiopods that indicate a 'Siegenian', now Lochkovian age. The bryozoan zoaria were yielded as bioclasts among others (tabulate coral fragments, punctuate and impunctuate brachiopod shells, crinoid ossicles) of a calcarenite, where clastic quartz appears of significant importance, with a micritic cement. The main Palaeozoic bryozoan orders are present in this fauna. Cystoporates may be encrusting or massive. Trepostomates either ramose or encrusting are common. Rhabdomesids are scarce while Fenestellids, more abundant present some diversity. Despite of clastic quartz, preservation of bryozoans is good even though a highier fragmentation of fenestellid zoaria more. Occurrence of such a bryozoan fauna, uncommon in 'rhenish', facies could be reported.

Dimorphic brooding zooids in the genus Adeona Lamouroux from Australia.

Philip E. Bock
Honorary Fellow, Deakin University, Melbourne, Australia

Patricia L. Cook
Associate, Museum of Victoria, Melbourne, Australia

The genus Adeona is a characteristic and common part of the Australian fauna, extending to the tropical Indo-West Pacific. The genus first appears in the fossil record of the Miocene of southeastern Australia. Zooid dimorphism has been recognised initially from subtle differences in the external appearance, which have not been described previously. Detailed examination has shown enlarged brooding zooids with marked differences from autozooids in the internal structure of the peristomes, and in the occurrence of a primary calcified orifice.

Deep-water Pleistocene bryozoan-sponge mounds, Great Australian Bight.

Yvonne Bone
Adelaide University, South Australia 5005, Australia

Noel P. James
Queen's University, Kingston, Ontario K7l 3N6 Canada

The Great Australian Bight is an enormous latitude-parallel shelf that has been the site of heterozoan carbonate deposition since Eocene time. Facing the Southern Ocean, the shelf has all the attributes of a high-energy, storm-dominated, mid-latitude carbonate system, with the depth of wave abrasion at ~70 metres water depth (mwd) and swell wave base at ~120mwd. The facies transition upslope into shallower water is marked by the presence of numerous bryozoan-rich build-ups. These structures, easily visible on seismic images, were drilled during ODP Leg 182. The mounds, at ~200 to ~ 350 metres water depth, are muddy and characterised by the prolific growth of numerous and diverse bryozoans. Build-ups have seafloor relief of up to 40 metres and are many hundreds of metres in lateral extent. None of the mounds is presently growing and the most recent are veneered with an ~7m layer of muddy skeletal sand. These stratigraphically- youngest mounds are inferred to have grown during glacial lowstands when upwelling was prevalent along the southern continental margin.

Bryozoans are diverse, with 78 genera identified. Large bryozoans are mostly fenestrate, flat robust branching, encrusting and delicate branching growth forms. Fenestrates are not diverse, with the four most common species evenly distributed. Flat robust branching forms are more diverse with Adeonellopsis, Bracebridgia, Caleschara, Labioporella and Porina the most abundant. Delicate branching forms are likewise fairly diverse and dominated by Idmidronea and Nevianipora. The most diverse and commonly most abundant forms are encrusting, with 28 species and no single genus dominant. Nodular-arborescent types, although conspicuous because of their size, are not diverse and are dominated by Celleporaria, with a lesser abundance of Celleporina. Sand- and finer-size bryozoans comprise the same species as above plus two species of foliose growth forms. The main difference is the higher ratio of delicate branching, articulated branching and articulated zooidal forms. Except for delicate branching cyclostomes, which are dominated by large numbers of Tubulipora, the growth forms are of moderate size.

Some mounds are composed of discrete metre-scale packages of floatstone separated by fine-grained packestone. Such packages display an overall coarsening-upward trend associated with increasing bryozoan diversity. Overall, the biota suggests a sponge-bryozoan community with bryozoans primarily epizooidal on sponges. The sponges are represented only by an abundance of spicules.

Observations of habitat and seasonal growth patterns of Parmularia reniformis, West Island, South Australia.

Kirsty M. Brown, Yvonne Bone and Rolf Schmidt
Department of Geology and Geophysics, University of Adelaide, Adelaide, South Australia 5005, Australia

Parmularia reniformis, also known as Lanceopora obliqua, is a distinctive bryozoan due to its discoid morphology and bright orange colour. It has previously been described as being common in waters deeper then 20m and attached to sandy substrate by an uncalcified organic stem in the Gulfs of South Australia (Bock, 1982).

Parmularia reniformis has now been identified from West Island, South Australia, in less than 6m water depth. It is found attached, by the organic stem, predominantly to the straw-like sheaths of the seagrass Posidonia sinuosa, instead of directly on or into the sandy sediment. It is also observed attached to sponges, abalone shells and the rhizomes of the seagrass Amphibolis griffithi. P. reniformis is a common species in the mixed seagrass beds at West Island and in one location 240 specimens per/m2 were counted. At this location, the size of the colonies varied from 10mm up to 50mm (average ~30mm). Previously, the maximum size described was 30mm.

The species was first observed at West Island in February 1999. Since then the same locality has been re-visited 10 times over a time span of 2.5 years. During this time it has been observed that there is a significant seasonal variation in both the density and the size of the specimens. The maximum size and density is found in late spring/summer (January/February), with a bleaching and die back of the colonies in late summer/early autumn (March/April). By winter (June/July) the species is all but absent. Small (<10mm) colonies re-appear by October.

Observations of the orientation of P. reniformis shows that, within a particular area, the majority are aligned in one direction within a given time. It is suspected that this orientation is related to current direction and that the discoid morphology causes the colonies to behave in a similar way to a weathervane i.e. the short axes faces into the current, the longest running parallel. It is not possible, without a current meter, to obtain accurate measurements of the current direction at the height above the seafloor where P. reniformis occurs. Water current in seagrass beds becomes deflected and the energy level reduced, by the presence of the seagrass, hence the prevailing current may have no connection with that of the current 5cm above the seafloor. Changing orientation with current direction has implications for feeding methods, growth patterns and habitat selection.

Larval release patterns in Antarctic bryozoans.

Juan M. Cancino and Felipe Torres
Facultad de Ciencias Universidad Católica de la Santísima Concepción, Casilla 297, Concepción, Chile

Hugo I. Moyano G.
Departamento de Zoología, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Casilla 160-C, Concepción, Chile

Most marine bryozoans in temperate waters incubate their larvae and release them following a circadian pattern related to light. Shallow water Antarctic bryozoans have been reported to sexually reproduce mainly in the summer months, which allows to ask if larval release in such bryozoans follows a similar circadian pattern to those from lower latitudes. The present study aims at answering such a query.

A total of 43 species of bryozoans were collected by scuba diving between 15 and 36 m depth at Doumer Island, (Base Yelcho of the Instituto Antártico Chileno, at 64º 52' 24" S, 63º 36' W) and kept in running seawater. The cycle of larval release was studied for 2-3 days after collection using larval release chambers.

The dominant species, Nematoflustra flagellata (Waters) and Himantozoum antarcticum (Waters) and their associated species released their larvae almost exclusively in daytime when photon flux density was above 0.5 µE m-2 s-1. Larvae release was almost absent from 11 at night until 5 in the morning. Therefore, larval release in Antarctic bryozoans follows a similar circadian pattern to shallow waters bryozoans in temperate and tropical waters. The significance of such a world-wide larval release pattern is discussed.

Financed by Project INACH 05/97.

Effects of clonal propagation on genetic variation in morphology: examples from the Paleogene (Coscinopleura) and the Neogene (Metrarabdotos).

Alan H. Cheetham
Department of Paleobiology, Smithsonian Institution, Washington, DC 20560-0121, USA

Results from rearing experiments with species of Stylopoma and, more recently, with Electra pilosa strongly support the use of the ratio between among-colonies and within-colonies variance for estimating genetic variation in zooid morphology in both living and fossil cheilostomes. This relationship is particularly important as a means of exploring the possible effects on genetic diversity, and thus on rates of speciation and extinction, of asexual propagation (by colony "regeneration") that is common in a variety of cheilostome species with free-living or erect growth forms. Coscinopleura and Metrarabdotos typically occur as erect ("adeoniform") colonies that often dominated bryozoan assemblages in the early (Paleogene) and late (Neogene) Cenozoic, respectively. Species of both genera are characterized by a paucity of brood chambers (ovicells), suggesting a reduced output of sexually produced larvae, in contrast to a higher frequency of ovicells in co-occurring erect genera. Nevertheless, the two genera differ greatly in the apparent incidence of asexual recruitment. Colony bases formed by regeneration from previously existing branches have been reported to dominate in Coscinopleura in the Danian of Denmark, whereas they have been found in only a few species of Metrarabdotos in the Neogene of tropical America. Moreover, the species of Metrarabdotos in which significant evidence of asexual recruitment have been found show no reduction in genetic variation (as estimated from among-colonies variance) relative to those in which all colony bases preserve evidence of sexual origin (ancestrulae). This paper will present new data based on material of Coscinopleura from the Paleogene of North America and Metrarabdotos from the Neogene of Europe further exploring the effects of clonal propagation on genetic variation.

Influence of colony morphology on associated biota diversity in four Bryozoa.

Silvia Cocito and Francesca Ferdeghini
ENEA, Marine Environment Research Centre, P.O. Box 316, 19100 La Spezia, Italy

Simona Pisaroni and Daniele Bedulli
Dipartimento di Biologia Evolutiva e Funzionale, Università di Parma, v.le delle Scienze, 43100 Parma, Italy

Increasing morphological complexity of habitat can be predicted to increase the diversity and abundance of organisms through increased living space, increased variety of feeding sources, modification of microenvironmental conditions and increased protection from predation. Samples of four erect, calcified (Cheilostomatida, Ascophorina) bryozoan species displaying different morphology, from slender, articulated branching structure to anastomosed laminae, were collected in the Ligurian Sea (northwestern Mediterranean). Colony shapes were assigned to four morphological types according to their increasing morphological complexity: Myriapora truncata (Pallas) to 'tree' type, Smittina cervicornis (Pallas) to 'bush', Sertella couchii (Hincks) to 'convolute laminae', Pentapora fascialis (Pallas) to 'anastomosed, convolute laminae'. Associated biota (both sessile and motile fauna with size > 5 mm) was identified to species or genus. A direct relationship between morphological complexity and species number of associated biota was found: Myriapora truncata (22 species belonging to 7 major taxonomic ranks), Smittina cervicornis (28 species, 7 major taxonomic ranks), Sertella couchii (37 species, 9 major taxonomic ranks), Pentapora fascialis (84 species, 13 major taxonomic ranks). Bryozoans were the most numerous colonising group: erect forms were more abundant on colonies with anastomosed, convolute laminae, and generally formed tufts which filled cavities among laminae. Encrusting forms were present on slender branches or at the base of tree and bush colonies. Bivalves, gastropods and errant polychaetes occurred inside cavities among laminae, whereas polychaetes serpulids encrusted preferably branches surface. Motile organisms, mainly crustaceans and fishes were seen or found exclusively among convolute laminae. Feeding strategies and ecological characteristics of associated biota were taken into account to interpret relationship between morphological complexity of the bryozoans and diversity of associated biota.

Notes on Exechonella (Cheilostomata) from southern Australia.

Patricia L. Cook
Associate, Museum of Victoria, Melbourne, Australia

Philip E. Bock
Honorary Fellow, Deakin University, Melbourne, Australia

The cheilostome genus Exechonella Duvergier, 1924 is represented by several species from the Tertiary and Recent of southern Australia, some of which appear to be undescribed. Two species-groups from the Tertiary of Victoria have erect, cylindrical branching colonies, but all known Recent species are encrusting. The samples examined are all frorn a depth range of 42-219 metres, and include large colonies composed of several thousand zooids. The relationships of the marginal frontal septular pores with both the frontal foramina and the visceral coelom have been investigated. In addition, the occurrence of avicularia and other kenozooidal structures derived from frontal septular pores is illustrated. The structure of frontal foramina in the Tertiary E. marginata demonstrates a major development of hypostegal coelom, unlike other described species.

Ordovician trepostome family classification.

Roger J. Cuffey
Department of Geosciences (412 Deike Bldg.), Penn State University, University Park, PA 16802, USA

A great many paleontologic studies depend critically upon species-level data, and bryozoan paleoecologic, reefal, biostratigraphic, and evolutionary investigations are no exception. A consistent and useable taxonomic framework is essential for understanding the similarities and relationships among those species. My experiences with North American Ordovician bryozoans suggest that the lowest (genus down) and highest (suborder up) taxa as recently modified are adequate, but that - for trepostomes - intermediate-level ones (families) in the present literature are difficult to diagnose, recognize, and apply. However, I find that several characters can be used to construct a pragmatically useable family classification for these trepostome species. Colony form, branch diameter, zooecial diameter, exozonal wall thickness, wall microstructure, hemiphragms, straight diaphragms, curved diaphragms, cystiphragms, mesopore frequency and openness, and acanthopore frequency and diameter all contribute to this systematic revision, which will be presented via diagnostic keys and referred-genera lists.

Molecular phylogeny and phylogeography of Tropical American Cupuladriidae from opposite sides of the Isthmus of Panama.

Matthew H. Dick
Department of Biology, Middlebury College, Middlebury, VT 05753, USA

Amalia Herrera-Cubilla
Center for Tropical Paleoecology and Archeology, Smithsonian Tropical Research Institute, P.O. Box 2072, Balboa, Republic of Panama

Jeremy B.C. Jackson
Center for Tropical Paleoecology and Archeology, Smithsonian Tropical Research Institute, P.O. Box 2072, Balboa, Republic of Panama and Scripps Institution of Oceanography, La Jolla, CA 92093-0244, USA

An approximately 485 bp DNA fragment of the 16S mitochondrial ribosomal RNA gene was sequenced individually from 174 cupuladriid colonies collected from eight areas along the Isthmus of Panama: Bocas del Toro, Gulf of Mosquitos, Costa Arriba, and San Blas on the Caribbean side; Gulf of Chiriqui, Taboga I., Las Perlas, and the Darien mainland on the Pacific side. A portion of each colony was saved as a voucher specimen. The aligned sequences fell into nine major haplotype groups differing from one another by 2.7-18.8% sequence divergence, levels consistent with species-level genetic distances. Major haplotypes were designated as Cupuladria 4, 5, and 6; Discoporella 2, 3A, 3B, 3C, 7, and 8. The major haploytpes were broadly distributed along the coast of Panama on one side or the other of the Isthmus, except for Discoporella 3B, which was collected only along the Darien mainland and showed a sharp break with Discoporellas 3A and 3C co-occurring at stations from Las Perlas westward to central Gulf of Chiriqui. A parsimony phylogeny of the major haplotypes, and including Discoporella umbellata from Florida, showed a clade of all Discoporellas embedded within a Cupuladria clade, a result consistent with an existing hypothesis of cupuladriid evolution based on morphological data. Cupuladrias 4 and 5 (aff. C. biporosa) were the sister group to a Cupuladria 6 (aff. C. surinamensis) + Discoporella clade. Cupuladrias 4 and 5 (4.6% divergence) appear to represent sister species derived from populations separated by the closure of the Isthmus. A clade comprising Discoporellas 3A-C (all Pacific) formed a sister clade to Discoporella 1 (Florida) + Discoporella 7 (Panama, Caribbean). The population ancestral to the Pacific Discoporella 3A-C clade appears to have diverged from the 1 + 7 clade before the closure of the Isthmus; however, an average divergence of 3.2% among Discoporella 3A-C suggests speciation within this lineage occurred during the Pleistocene. Discoporellas 2 and 8 (both Caribbean) showed an average divergence of 11.9% from the other Discoporellas. Cupuladria 6 showed an average divergence of 13.4% from the Discoporellas, and 13.9% from Cupuladrias 4 and 5. The cupuladriid sequences showed two patterns of variation within the major haploypes. Cupuladria 5 and Discoporellas 2, 3A, 3B, and 7 showed 38-72% of sequences identical to the respective haplotype consensus sequence, with the rest consisting of usually unique minor haplotypes with 1-3 scattered point mutations each. In contrast, Cupuladria 4 and 6 and Discoporella 3C and 8 showed groups of sequences (sub-haplotypes) within major haplotypes which differed from other sub-haplotypes by sharing fixed point mutations at 3-7 sites. In some cases, subhaplotypes corresponded to geographical subdivisisions of the ranges of the major haplotypes. Proportions of sexually versus clonally initiated colonies were determined for the major haplotypes, using the voucher specimens. Among haplotypes with little population substructure, there was no apparent correlation with mode of reproduction. Haplotypes which showed population substructure generally showed a higher frequency of origin from larvae, although this needs to be tested with larger sample sizes.

Taxonomy, diversity and abundance of the Late Cretaceous Bryozoa from Egypt: their paleoecologic indicators.

Moharem M. Elgamal and Mona A. El Bosraty
Geology Department, Faculty of Science at Damietta, New Damietta, Egypt

A. Ziko
Geology Department, Faculty of Science at Zagazig University, Zagazig, Egypt

The late Cretaceous bryofauna of Abu Roash area in the vicinity of Cairo, Egypt reflects the changes in the depositional environment. The Cenomanian with deltaic sediments is characterized by low diversity and low abundance. The bryofauna were successful reef builders during the Turonian. They were second to the calcareous algae in importance within the build-up, where they attained wide diversity and abundance, but mostly microporids and their likes. They were not mostly encrusting forms. Many of them managed to develop cylindrical, subcylindrical and dendroid zooaria. The bryozoans of the Turonian build-up were also characterized by relative small size; about 60% of the size of normal Cretaceous bryozoans. A drop in diversity and abundance is noticed by the termination of the reef build-up drop during the Coniacian. Within the late Cretaceous chalk 'Campanian-Maastrichtian', the bryofauna were the main lithic framebuilt within planktonic forams. The chalk was in a great part a product of micritization. The zooecia of the chalk bryozoans are extremely minute; about 40% of the normal bryozoan size. The taxonomy and the status of the studied bryofauna have been elaborated with special emphasis on the new taxons. NOT PRESENTED.

Bryozoans from the northern coast of Egypt.

Yasser A. El Safori
Department of Geology, Faculty of Science, Ain Shams University, 11566 Cairo, Egypt

The Recent bryozoans of the Mediterranean coast of Egypt have few records in contrary with the Red Sea coast. Fifteen species (4 cyclostomes, 8 anascans, 3 ascophorans) are separated from west Alexandria and Baltim beach sediments. Besides the normal substrate of mollusk shells and rock fragments, encrusting forms use other artificial substrates such as concrete and building bricks. Because of the high wave action in west Alexandria, few encrusting forms are recognized, however on the Baltim coast the encrusting forms occur more widely.

Cretaceous bryozoans of Egypt and their palaeogeographic significance.

Yasser A. El Safori
Department of Geology, Faculty of Science, Ain Shams University, 11566 Cairo, Egypt

The Cretaceous bryozoans of Egypt seem to be preserved only in the lower Senonian (Coniacian-Santonian) sediments, with a moderate diversity and limited distribution. In older sequences they are apparently absent (Cenomanian) to very rare (Turonian). In younger deposits of the upper Senonian (Campanian-Mastrichtian) they are not recorded. Fifteen species, mostly anascans, are separated from the northern outcrop sections (Gulf of Suez and Western Desert). The limited distribution of the Egyptian Cretaceous fauna could be a reflection of their high ecological sensitivity to low saline waters dominated during that time in south Egypt and Sinai.

Miocene facies and bryozoans of Siwa Oasis, Egypt.

Yasser A. El Safori
Department of Geology, Faculty of Science, Ain Shams University, 11566 Cairo, Egypt

The middle Miocene surface section of Siwa Oasis is rich in bryozoans. Sixty two bryozoan species are systematically studied (19 cyclostomes, 19 anascans, 24 ascophrans). According to the field observations, facies analysis, bryozoan growth-forms, the succession is separated into four facies units namely, from base to top: (1) Marly limestone and shale, with mostly flexible, highly diverse bryozoans; (2) Cross-bedded limestone, with mostly flexible, diverse bryozoans; (3) Chalky limestone and shale, with mostly free living, diverse bryozoans; (4) Chalky limestone, with mostly rigid, low diverse bryozoans. The paleoecologic parameters as depth range, rate of sedimentation, water turbulence are concluded for each unit.

Colony morphologies and missed opportunities during the Cincinnatian (Ordovician) bryozoan radiation: an example from Heterotrypa frondosa (Trepostomata).

J. Mark Erickson
Department of Geology, St. Lawrence University, Canton, NY, 13617, USA

David A. Waugh
Department of Geology, Kent State University, Kent, OH 44242, USA

Renewed interest in Paleozoic Bryozoa is focusing upon zoarial architecture and colony morphologies. Recovery and reconstruction of a major portion of a Heterotrypa frondosa (d'Orbigny) colony has provided basis for study of functional morphology, habitat tolerances and growth strategies of that species. Coupled with observations of the morphologies of sympatric taxa occurring in the same Ordovician (Cincinnatian: Maysvillian) strata of the upper Fairview and lower Bellevue Formations there is evidence that fair-weather wave resistance was achieved by multiple species during this depositional sequence.

Strata of the Fairview-Bellevue interval have long been recognized for the numerous large fronds or blades of several bryozoan taxa. We collected a fragmented specimen of H. frondosa from a 0.3 m shale bed at Sharonville, Ohio. Careful cleaning allowed re-assembly of a zoarium measuring 13 cm high and 26 cm wide. This unique specimen permits inference of several paleoecological relationships deserving description and discussion.

We assume the colony grew from a base encrusting the hardground surface of the bioclastic limestone bed underlying the entombing shale. A growth sequence interpreted from the specimen includes: encrusting a hardground substrate - developing a triad of vertical coalescing blades - bifurcation of original blades - production of archways and windows - reorientation of blade growth axes into the horizontal plane - coalescence of adjoining blades to produce chambers - vertical blade growth resumes atop chamber openings - cycle repeated. This astogenic, cyclical growth sequence produced a heavily buttressed wave-resistant skeleton. Such colonies were numerous for a brief time interval in the Late Ordovician in shallow waters above storm wave base.

Taphonomic analysis demonstrates that the colony was broken from its base, tumbled and de-bladed to the level of the first chambers, became stabilized in a partially overturned position and was buried after an episode of encrustation by species of Cuffeyella, Cornulites and unidentified bryozoans. Subsequently, it was entombed in shale and crushed under lithostatic pressure.

Presence of wave-resistant trepostome colonies on Cincinnatian carbonate flats suggests that creation of biogenic structures analogous to modern cnidarian reefs lay within the ecological grasp of these massive bryozoans at this instant in geologic time. Only a self-replicating community structure of seral succession leading to deposition of an interlocking bioclastic framework failed to evolve. That this opportunity was not seized appears, locally, to have been the result of sea level or tectonic instability, shelf morphology, climatic instability, sediment influx or a combination of these extrinsic factors. Thus, environmental instability, not biological inability, prohibited evolution of a stable seral succession of a local fringing-reef type. Globally, the terminal Ordovician extinction coupled with the absence of tropical, stable plate margins gave no zoogeographic refugium where final interactive, reef-type, framework-building bryozoan community structure might develop to a self-perpetuating completion of either a barrier or fringing type. Hypersaline Silurian reefoid habitats were generally unacceptable to Bryozoa. The next appropriate ecological window was occasioned by development of the Tethys Seaway when the Cnidaria seized the opportunity that the trepostomate Bryozoa had missed.

Systematics and biogeography of the Permian Bryozoans in Europe.

Andrej Ernst
Institut für Geowissenschaften der Universität zu Kiel, Olshausenstr. 40, D-24118 Kiel, Germany

Bryozoan faunas of the Zechstein and NW-Tethys (including here Carnic Alps; Sicily and Tunisia) were investigated and analysed on the base of modern aspects of systematics. The Zechstein Sea existed for a short time in the Upper Permian, presumably during the Tatarian. Contrary, the Tethys existed during almost the whole Permian in the region of South Europe and Northern Africa. Most of the Zechstein bryozoan fauna is represented by fenestellids. This fauna was compared with other Permian fenestellid bryozoans on the base of interior characters. Contrary to existing descriptions of Zechstein species from elsewhere, which are based on external characters. This improved their biogeographical significance. The comparison showed no resemblance between Zechstein and Tethian fenestellid faunas. However, external characters such as growth habits are mostly convergently developed. Species of the genera Acanthocladia, Synocladia, Penniretepora and Kalvariella from the Zechstein show significant resemblance in their interior characters. They possess like autozooecia and heterozooecia which are autozooecia with spherical ovicells. They possibly diverged from some polyporinids of the Arctic which possess like autozooecia and heterozooecia. In addition, Zechstein bryozoan fauna shows close relations to Upper Permian (Kazanian) faunas of Urals and Nevada. In the NW-Tethys, bryozoan faunas are very diverse in the Lower Permian and becoming reduced in the Upper Permian. Lower Permian bryozoans of the Carnic Alps show close relations to Uralian and Australian bryozoan faunas. In the Upper Lower Permian (apparently Early Artinskian) the Uralian Seaway was closed. This event effected the composition of Uralian and Tethian bryozoan faunas. So, no Uralian bryozoan species could be stated in the Upper Permian of Sicily and Tunisia. Moreover, the Tethian faunas show distinct relations to Australian faunas.

The use of the fluorescent probe DASPEI as a taxonomic tool in the ctenostome bryozoan Bowerbankia.

Nicola Fenton and Mary Spencer Jones
Department of Zoology, The Natural History Museum, Cromwell Road, London SW7 5BD, UK

Joanne S. Porter and Andrea Wäschenbach
Department of Biological Sciences, University of Wales, Swansea, Singleton Park, Swansea SA2 8PP, UK

Problematic genera, such as the bryozoan Bowerbankia, have often been difficult to identify. Larva of Bowerbankia gracilis and Bowerbankia imbricata were collected and treated with the fluorescent probe DASPEI. Results show that DASPEI can be use as an aid to the identification of morphological features in larval ctenostome species.

The shallow water bryozoans of the west coast of South Africa.

Wayne Florence
Department of Zoology, University of the Western Cape, Private Bag X17, Bellville, 7535, Cape Town, South Africa

Our understanding of the Bryozoan fauna around South Africa is fragmented and has become largely out-dated. It is suggested that the Bryozoan fauna off South Africa comprise a rich and taxonomically diverse assemblage of species, and that the few previous studies on this region have failed to reveal more than a fraction of it’s potential complexity. In 1999 an attempt to rectify this situation was initiated, when an inventory of the bryozoan fauna of a selected region along the west coast of South Africa was started. To date 145 specimens were collected and yielded 34 species in 24 genera and 19 families (2 species belong to the order Ctenostomata and the rest are Cheilostomes). Of the 34 species 12 are new to science. The most striking aspect of the west coast bryozoan fauna (based on underwater observations) is its low species richness (ie., Number of species per unit area) and high levels of dominance (ie., one or a few species representing most of the individuals in the community). These patterns are discussed and some generalities on the affinities of the South African bryozoan fauna to that of neighbouring countries are made.

Contribution of sibling speciation to marine biodiversity: preliminary results of Celleporella worldwide genetic differentiation using nuclear and mitochondrial genetic markers.

Africa Gómez, David H. Lunt and Gary R. Carvalho Department of Biological Sciences, University of Hull, Hull, HU6 7RX, England, UK

Roger N. Hughes School of Biological Sciences, University of Wales, Bangor, Gwynedd LL57 2UW, Wales, UK

Sibling species lack conspicuous diagnostic morphological characters, but are identifiable from genetical, biochemical, behavioural or ecological features. The widespread presence of sibling species has been recently acknowledged in the sea, and has been explained by the dominant role of chemoreception in the recognition systems of aquatic invertebrates. Many marine morphological species with apparently widespread or cosmopolitan distributions seem to be comprised of geographically localised sibling species. We have used the encrusting cheilostome bryozoan Celleporella hyalina as a model organism to investigate the extent of molecular genetic diversification and cryptic speciation in a cosmopolitan species and unravel its the causes. Celleporella presents several desirable features, among them its clonal character, which permits a strict control of the genotype, and relative ease of laboratory culture. There is a wealth of background knowledge on its reproductive biology, and crosses between different colonies can be readily made in the laboratory. C. hyalina colonies brood their embryos, and, after being released, larvae settle whiting a few hours, providing opportunities for local differentiation. Samples from most of the known range of C. hyalina were collected and wild colonies preserved in ethanol. DNA from colonies was extracted using a standard CTAB method. Bryozoan-specific primers were optimised and used to amplify a mtDNA region (Cytochrome Oxidase I gene) and a nuclear region (Elongation Factor 1-alpha). The poster will report on the level of geographic variability found, and the implications of this diversification will be discussed.

Late Cretaceous-Danian 'porinids' - mixed frontal shields and evidence of polyphyly.

Dennis P. Gordon
National Institute of Water and Atmospheric Research, P.O. Box 14-901 Kilbirnie, Wellington, New Zealand

Ehrhard Voigt
Geologisch-Paläontologisches Institut und Museum, Universität Hamburg, Bundesstraße 55, D-20144 Hamburg, Germany

Putative porinids (Cheilostomatida) from the Late Cretaceous and Danian of northwestern Europe exhibit a varied range of external frontal-shield morphologies. Some frontal shields are relatively featureless or merely dimpled, others have numerous foramina of various diameters and these are surrounded by raised ridges in some species. The complex surface topography of some frontal shields defies interpretation when viewed only externally but exceptional preservation of many taxa in the European chalk allows fracture of zooids and SEM observation of frontal-shield interiors. A number of species have umbonuloid shields whereas others have frontally concealed spinocysts of well-developed costae. External foramina in many species are cavities associated with frontally opening areolar septular pores, avicularia, and spiramina. New genera are proposed for some species and their family attributions are discussed.

Bryozoan fauna of Green Island, Taiwan - first indications on biodiversity.

Tea Gluhak
Jurkoviceva 10, 10000 Zagreb, Croatia

Aleksandar Popijac
Laboratory for Animal Ecology, Department of Zoology, Faculty of Science, University of Zagreb, Rooseveltov trg 6, 10000 Zagreb, Croatia

Jane E. Lewis
Institute of Marine Biology, National Taiwan Ocean University, 2 PeiNing Road, Keelung 202, Taiwan, ROC

As part of a new initiative to inventory the poorly known Taiwan bryozoan fauna, this poster reports on the faunistic results of two workshops that processed and identified collections from a five day field trip to Green Island, southeast Taiwan. The annotated list presented here includes 25 genera. Several taxa including species in Amastigia, Caberea, Canda, Catenicella, and Parasmittina are reported for Taiwan for the first time. Cheilostomates predominate and only a few cyclostomate taxa were determined, then only to genus. These completely new data from Green Island probably reflect the taxonomic richness of the bryozoan fauna in the tropical western Pacific biogeographic region. This region still remains relatively uninventoried, but a regional inventory bryozoan workshop is planned for June, 2002.

New genus of Adeonidae (Bryozoa: Cheilostomata) from the Western Kamchatka shelf of the Sea of Okhotsk.

Andrei V. Grischenko and Shunsuke F. Mawatari
Systematic and Evolution, Division of Biological Sciences, Graduate School of Science, Hokkaido University, Sapporo 060-0810, Japan

A new monotypic genus and species of Adeonidae, Kubaninella relicta, named in memory of Russian bryozoologist, Dr Andrei A. Kubanin, is described from the Western Kamchatka shelf of the Sea of Okhotsk. Yellow colonies with a pale growing margin form patches of incrustations cemented to pebbles and occasionally to broken bivalve shells of Chlamys at the depth of 78-81 m.

Ancestrula is tatiform, relatively circular, with narrow gymnocyst and a large oval opesium, surrounded by jointed hollow vertical spines. Priancestrular zooids are small, clearly demarcated, with a thin and remarcable convex frontal shield and with rounded orificies. One to two pairs of hollow oral spines present in some zooids from primary zone of astogenetic change. Frontal shield development is umbonuloid with a series of scattered marginal areolar pore canals and a spiramen in the central depression. Frontal rises distally into a thin peristom with bulge-like mucro in front of the orifice. A small suboral avicularium with acute triangular mandible is associated with a distolateral slope of mucro. Ovicells and gonozooids are unknown.

New genus is close to Adeonella Busk, Reptadeonella Busk, and Tremogasterina Canu, but differ from all of them by the nature of ancestrula, form and shape of mucro, position of avicularia, and by some other characteristics. Distribution of an overhelming majority of Adeonidae is limited by warm temperate waters (Hayward 1988), and thus the finding of K. relicta within the high-boreal region represents an undoubted interest.

Many colonies of K. relicta were collected to be overgrown by other sessile organisms, namely hydroids, sponges and other bryozoan species. Colonies of K. relicta probably unable to deter the overgrowth, because of their solid attachment to substrata by all zooids, comparatively small size of colonies (usually not exceeding 15-20 mm), and apparent impossibility of elevating the growing margin above the substratum. The production of long and distally-directed spines at the growing edge of the zooids in early astogeny perhaps represents the only way of decreasing the rate of overgrowth by spatial competitors.

Partitioning sources of morphologic variation within and among bryozoan colonies: genetic, microenvironmental and within colony growth/packing constraints (Electra pilosa).

Steven J. Hageman
Department of Geology, Appalachian State University, Boone, NC 28608, USA

Micha M. Bayer
Department of Systematics and Evolution, Royal Botanic Garden Edinburgh, Inverleith Row, Edinburgh EH3 5LR, UK

Christopher D. Todd
Gatty Marine Laboratory, School of Environmental and Evolutionary Biology, University of St. Andrews, St. Andrews, Fife KY16 8LB, UK

Using clonal replicates of Electra pilosa colonies grown in controlled environmental conditions, it is possible to partition sources of morphological variation of skeletal hardparts into their geneotypic, environmental and interaction components. Preliminary studies demonstrate that these factors account for only about 40% of variation among measured zooecial characteristics, resulting in a residual (variation unaccounted for in the model) of 60%.

Several factors may responsible for unaccounted for variance such as microenvironmental (subcolonial) environmental variation, and ontogenetic/astogenetic effects. These effects can be tested for indirectly in an analysis of variance in a nested factorial design for five zooecial characteristics (opesia and zooecia width and length and spine number): three Genotypes (two Colony Replicates per genotype (three 5x5 Patches of zooecia per colony replicate (five Columns of zooecia, five Rows of zooecia))).

Post-hoc comparison of means demonstrates (1) a high degree of significance among genotypes for all characters (p < 0.01); (2) mixed significance among colony replicates (= microenvironmental variation); (3) mixed levels of significance among patches within replicates; (4) no significant difference (p < 0.01) for column, row, or column x row interaction. This suggests that there is minimal systematic variation in the placement of zooids within a patch, and that much of the residual variance in all of these models derives from variation among individual zooecia.

Free-living cheilostome bryozoans from the Upper Cretaceous of Norfolk.

Eckart Håkansson
Geological Institute, University of Copenhagen, Øster Voldgade 10, DK - 1350 Copenhagen, DENMARK

Paul Whittlesea
8 Eaton Old Hall, Hurd Road, Eaton, Norwich, Norfolk NR4 7BE, UK

Cheilostome diversity and density increases dramatically up through the Upper Cretaceous, but although marine Upper Cretaceous strata cover vast areas on all continents, bryozoans are far from evenly distributed, and the bulk of the increase is in fact recorded from the Northwestern European chalk sea. The overall pattern in diversity, density, and distribution is matched by the free-living cheilostomes, albeit with a notable delay. From a very slow start late in the Turonian the free-living cheilostomes similarly reach an overwhelming peak in the Maastrichtian, with about 100 species presently known from Northwestern Europe. But whereas cheilostome diversity in general was at its highest in the more sandy, shallow water carbonates surrounding the basin, free-living cheilostomes reached their highest diversity in the basinal chalk facies. However, it is not known whether free-living evolution primarily was centered in the shallow water carbonate facies and subsequently recruited into the deeper water chalk, or whether parallel evolution was taking place also in the deeper water facies occupying most of the basin.

Unfortunately bryozoan densities in pre-Maastrichtian chalk in Northwestern Europe is usually exceedingly low and only a few good possibilities are available to actually trace the pre-Maastrichtian part of free-living evolution in continuous sections - the Coniacian-Campanian section in Norfolk provide one of the best examples, which has been extensively studied for centuries.

This talk present an overview of the younger part of the Norfolk chalks, their free-living faunas, as well as the position of these faunas with respect to the overall evolution in the basin.

Bryozoan distribution in a Messinian reef complex of western Algeria.

Assia Hamdane
Département des Sciences de la Terre, Université Houari Boumédiène, BP 32 El Alia, Bab Ezzouar, Algeria

Pierre Moissette
UFR Sciences de la Terre, Université de Lyon I, 27 Bd du 11 Novembre, 69622 Villeurbanne Cedex, France

At the end of the Miocene (Messinian), the peripheral basins of the Mediterranean exhibit a huge development of widespread carbonate platforms corresponding to an important phenomenon of bioconstruction (scleractinians, coralline algae, bryozoans, and serpulids) and of bioaccumulation (molluscs, echinoderms, foraminifers). In the north-western part of Algeria, in the Chelif basin, the Djebel Dzioua is a reef complex where coral assemblages are dominated by the genera Tarbellastraea and Porites associated with bivalves (oysters). This bioherm is approximately 20 m long and 3m high.

The qualitative and quantitative distribution of the associated bryozoans (relative proportion of the zoarial growth forms and species diversity) reveals a zonation within the bioherm. The use of the bryozoan distribution in order to position the bioherm in the ecological succession based on corals (James and Bourque model) appears to be suitable.

A small number of zoarial growth forms (membraniporiform, celleporiform, and cellariiform), is indeed observed at the base of the bioherm, corresponding to the stabilization of a shoal by oysters and corals. It is followed by a colonization, characterized by an increase in the number of zoarial forms, with predominating massive and lamellar species, together with a small number of erect colonies (adeoniform and reteporiform). A diversification of species belonging to various zoarial growth forms then occurs at the top of the bioherm with an increase of the space (surfaces and cavities) available for colonization by reef dwellers. Other constructions above the bioherm and also laterally are elaborated by vermetids and serpulids bound to the coral reefs. The bryozoans associated to these secondary frame builders show a higher number of zoarial forms with a predominance of celleporiform and membraniporiform species.

The development of building organisms (corals, bryozoans, vermetids, and annelids) and the indications given by zoarial forms and extant species suggest a palaeodepth of about 20m propitious to coral development but also to the proliferation of organisms using the various habitats offered by the environment (crevices, cavities).

Bryozoan assemblages from the Tertiary of Antarctica.

Urszula Hara
Department of Geological Museum, Polish Geological Institute, Warsaw 00-975, Poland

Bryozoan assemblages recorded from the marine and glaciomarine sediments of Eocene on Seymour Island (Marambio), Antarctic Peninsula and Oligocene-Miocene of King George Island (South Shetland Islands) exhibit a rich and diversified element of the Cenozoic ecosystems of West Antarctica (Gaÿdzicki, Pugaczewska, 1984; Hara, 1998, 2001).

The richly fossiliferous Eocene sandy, shallow-marine-estuarine clastic succession of the La Meseta Formation on Seymour Island contains the most numerous and highly distinctive bryozoan fauna, not recorded from Antarctica until 1994 (Gaÿdzicki and Hara 1994, Hara 1998, 2001). The most common and characteristic are massive, multilamellar either hemispherical or mound-shaped bryozoan colonies, often with diameter exceeding 10 centimeters which occur within a 2 m thick interval of the basal transgressive facies (Telm1 unit). Bryozoans in Telm1 are associated with surprisingly well-preserved and rich invertebrate fauna, which indicates warm to temperate-warm climate during the deposition of this part of the formation. By contrast bryozoans in the upper part in the formation (Telm6-7) are impoverised and reduced in taxonomic composition. A sharp decline in bryozoan diversity from 30 genera in the lower part to only two genera in the upper one (Telm6-7) is most probably connected with climatic changes and the sedimantary environment in the Antarctic marine ecosystems at the end of Eocene (Zinsmeister, Camacho, 1982; Dzik, Gaÿdzicki, 2001). The isotopic results as well as a substantial decline in diversity of paleoflora indicate a climatic-event at the time of deposition of the upper part (Telm6-7) (Gaÿdzicki et al., 1992; Doktor et al., 1996).

The Oligocene bryozoan assemblage recorded from the glacio-marine sediments of the Polonez Cove Formation on King George Island (South Shetland Islands) and Lower Miocene of Cape Melville Formation distinctly differ from the bryozoan assemblage of Seymour Island in a poorer taxonomic diversity and the morphology of the bryozoan growth-forms (Hara, 1998).

The Eocene-Oligocene extinction in marine and terrestrial biota (especially among the warm-water taxa) is confirmed i.e. by the global cooling (Berggren i Prothero 1993; Prothero 1994). The diversification of the bryozoan assemblages in the paleontological record of Antarctica is connected with the climatic changes and it documents their routes of evolution and paths of migration during the early Cenozoic.


Berggren W.A., Prothero, D.R. 1993. Eocene-Oligocene climatic and biotic evolution: an overview. In: D.R. Prothero and W.A. Berggren (eds), Eocene-Oligocene climatic and biotic evolution: 1-24.
Doktor M., Gaÿdzicki A., Jerzmañska A., Porêbski S.J., Zastawniak E. 1996. A plant-and-fish assemblage from the Eocene La Meseta Formation of Seymour Island (Antarctic Peninsula) and its environmental implications. In: A. Gaÿdzicki (ed.), Palaeontological Results of the Polish Antarctic Expeditions. Part II. Palaeont. Polon. 55, 127-146.
Dzik J., Gaÿdzicki A., 2001. The Eocene expansion of nautilids to high latitudes. Palaeogeogr., Palaeoclimat., Palaeoecol.
Gaÿdzicki A., Pugaczewska H., 1984. Biota of the "Pecten Conglomerate" (Polonez Cove Formation, Pliocene) of King George Island (South Shetland Islands, Antarctica). Studia Geol. Polon., 79: 59-120.
Gaÿdzicki A., Gruszczyñski M., Hoffman A., Makowski K., Marenssi S.A., Haas S., Tatur, A. 1992. Stable carbon and oxygen isotope record in the Paleogene La Meseta Formation, Seymour Island Antarctica. Antarctic Science, 4: 461-466.
Hara U., 1998. Mszywioy kenozoiku Antarktyki Zachodniej. Kosmos, 47: 431-438.
Hara U., 2001. Bryozoans from the Eocene of Seymour Island, Anatrctic Peninsula. In: A. Gaÿdzicki (ed.), Palaeontological Results of the Polish Antarctic Expeditions. Part III. Palaeontol. Polon., 60.
Prothero D.R., 1994. The Late Eocene-Oligocene extinctions. Ann. Rev. Earth Planet. Sci., 22: 145-165.
Zinsmeister W.J., Camacho H.H., 1982. Late Eocene (to possibly earliest Oligocene) molluscan fauna of the La Meseta Formation of Seymour Island, Antarctic Peninsula. In: C. Craddock (ed.), Antarctic Geosciences, University of Wisconsin Press, Madison: 99-304.

Large erect bryozoans as indicators of climate change? Clues from NW Mediterranean assemblages.

Jean-Georges Harmelin Centre d'Océanologie de Marseille, CNRS-UMR 6540, Station Marine d'Endoume, 13007 Marseille, France

A mass mortality event affected several suspension-feeder, sessile, invertebrate taxa along the the NW Mediterranean coasts from Liguria (Italy) to Provence (France) in late summer and early autumn 1999. This event occurred concomitantly to an exceptional warming of the sea that remained steady for five weeks. The most affected taxa were gorgonians (Paramuricea, Eunicella, Corallium) and several sponges. Effects of this mortality event were assessed on six large rigidly erect bryozoans (Adeonella calveti, Myriapora truncata, Pentapora fascialis, Porella cervicornis, Sertella spp., Turbicellepora avicularis). This assessment benefited from previous in situ quantitative records of abundance, colony size and fouling rate made in 1998, which were replicated at the same season in 2000 in three localities. The most evident post-event change observed in these species was a clear increase in fouling of their colonies by various opportunist colonisers. This phenomenon is an apparent consequence of the partial mortality of colonies. As for other impacted invertebrates, intensity of mortality varied among species and sites. Indirect effects of this event on large erect bryozoans may result from mass mortality of the large gorgonians. Subsequent toppling and degradation of their skeletons may induce a dramatic habitat loss to species (e.g. T. avicularis) which are closely associated to slender, stem-like substrates deployed in the water colum. The actual causes of this mass mortality are unknown and might involve a thermal stress only indirectly, e.g. through induced development of pathogens. However, it is assumed that this exceptional thermal event is a sign of the general warming trend observed in the Mediterranean, which is attested by increase frequency or arrival of southern species. Hence, the further repetition of events of this type is conceivable and might lead to profound changes in Mediterranean sessile communities.

Effects of pollution on bryozoan diversity in Mediterranean rocky bottoms.

Jean-Georges Harmelin and Sylvain Capo
Centre d'Océanologie de Marseille, CNRS-UMR 6540, Station Marine d'Endoume, 13007 Marseille, France

Effects of pollution on bryozoans have been poorly investigated at assemblage level despite the place of this group in rocky reef communities. Pollution examined here is mainly of urban origin and comes from used waters of the Marseilles area, which are discharged at the sea surface on a steep rocky coast submitted to westward dominant circulation. This area provides abundant potential habitats to bryozoans (boulders, overhangs, cavities) at various distances from the sewer outlet. Diversity of bryozoans was assessed at graded steps along pollution gradients (0.4 km to 5.2 km from outlet) by considering three aspects of the bryozoan fauna that allowed site comparisons: (i) the cryptic fauna colonising underfaces of boulders; (ii) the large erect bryozoans from vertical walls; (iii) the 5 and 12 month-old assemblages colonising artificial substrates. In each of these fauna categories diversity and abundance decreased abruptly when distance to the pollution source decreased, particularly in downcurrent sites. At 1.3 km from the outlet the mean number and mean percent cover of species occurring in cryptic habitats were respectively about 3 and 2 times higher in the eastern site than in the western site. A set of species particularly frequent in the least degraded sites (e.g. Entalophoroecia deflexa, Hincksina flustroides, Fenestrulina malusii, Porella concinna) was excluded from the most polluted areas while a few species (Schizoporella longirostris, Tubulipora aperta) were particularly successful in those sites. Large erect cheilostome species proved to be highly sensitive to pollution, except Myriapora truncata, which was relatively tolerant.

Preliminary report on the systematic of Tropical American Cupuladriidae from opposite sites of the Isthmus of Panama.

Amalia Herrera-Cubilla
Center for Tropical Paleoecology and Archeology, Smithsonian Tropical Research Institute, P.O. Box 2072, Balboa, Republic of Panama

Matthew H. Dick
Department of Biology, Middlebury College, Middlebury, VT 05753, USA

Jo Ann Sanner
National Museum of Natural History, Smithsonian Institution, Washington, USA

Jeremy B.C. Jackson
Center for Tropical Paleoecology and Archeology, Smithsonian Tropical Research Institute, P.O. Box 2072, Balboa, Republic of Panama and Scripps Institution of Oceanography, La Jolla, CA 92093-0244, USA

Seventeen characters of skeletal morphology of cupuladriid bryozoans (Family Cupuladriidae, genera Cupuladria and Discoporella that fall in 7 major haplotype groups for a fragment of the 16S mitochondrial RNA gene were measured or scored. Individual colonies were collected from seven geographical regions along the Caribbean and Pacific coasts of the Isthmus of Panama, from September 1999 to June 2000.

The morphological characters included zooid length and width, orifice length and width, vibracula avicularia length and width, vibracula-zooid length ratio, vibracula-zooid width ratio, number of opesiules, number of pores in the autozooidal frontal shield, number of vicarious avicularia, length and width of vicarious avicularia, length and width of the vicarious avicularian orifice, sector’s area, number of pores per sector.

Preliminary Nested ANOVA analyses showed that Discoporella differ consistently in 9 of the 10 characters. Significant differences in orifice (opercula) length and width permit discrimination of major haplotype groups between regions (Caribbean and Pacific combined) and among major haplotypes within regions. However, to test the utility of these morphological characters to discriminate species it will be necessary to determine empirically the numbers of species per genera by a sequence of multivariate analyses, similar to those used previously to discriminate species of cheilostomes. Additionally, ecological studies will be necessary to confirm if the species so identified, have different life habits and life histories.

Freshwater bryozoan remains from the Molteno Formation (Upper Triassic) of South Africa.

Anna Hoernig and Rolf Kohring
Institut fuer Palaeontologie, Freie Universitaet Berlin, Malteserstraße 74-100, Haus D, 12249 Berlin, Germany

Fossil statoblasts of freshwater Bryozoa (Phylactolaemata Allman 1856) are known from Quaternary, Oligocene, Eocene and Lower Cretaceous deposits. All known specimens have been found mainly in lacustrine deposits. Since the marine orders of Bryozoa are known from the Early Palaeozoic, a much older origin of freshwater Bryozoa can be suggested.

From the Upper Triassic Molteno Formation of South Africa more than 1000 specimens of small biconvex and circular-shaped statoblasts have been discovered. They are of two size classes (0.6 mm and 1 mm in diameter), reflecting two different taxa. Nearly all specimens are concentrated on bedding planes at the locality Birds River, which is of lacustrine origin. The other Molteno locality to have yielded statoblast is Kapokkraal, which was deposited in an abandoned channel within a braided-river system.

Evidence for obligate outbreeding in the Celleporella hyalina species complex.

Roger N. Hughes, Peter Wright and Patricio H. Manríquez
School of Biological Sciences, University of Wales, Bangor, Gwynedd LL57 2UW, Wales, UK

Simultaneous hermaphroditism affords the potential for self fertilization, which could be selectively advantageous under restricted opportunity for outbreeding. Such restriction may apply to free-spawning sessile invertebrates, such as bryozoans, when the vagaries of settlement place colonies at a distance from potential partners. Contrary to this scenario, however, most populations studied within the Celleporella hyalina species complex did not show evidence of self fertilization. Colonies kept in reproductive isolation failed to produce embryos or produced few, abortive embryos, whereas controls kept together in culture vessels copiously produced viable embryos. These results, together with previous work demonstrating severe inbreeding depression and the capacity of juvenile colonies to store allosperm, suggest that Celleporella hyalina is typically an obligate outbreeder.

Report of some new solitary entoprocts from Okinawa Island (Ryukyu Archipelago), Japan, with comparative observations of their budding modes and buds’ characteristics.

Tohru Iseto
Department of Chemistry, Biology and Marine Science, Faculty of Science, University of the Ryukyus, Nishihara, Okinawa 903-0213, Japan

Previous surveys in Japan described 29 species of phylum entoprocta including both colonial and solitary form. However, these surveys did not include species from Ryukyu Archipelago (southern part of Japan). Indeed, there were no data available for this phylum in this region. Thus, a survey of this phylum has been initiated in March 1999 in Okinawa Island. First results show that at least ten solitary entoprocts are living in this coralline biotope. Eight of them are revealed unidentified species. Interspecific variations in their budding mode and bud’s morphological and behavioral characteristics are also reported in order to suggest an improved classification of solitary species.

Bryozoan on disarticulated and living bivalve shells from temperate waters of Japan and New Zealand: taxonomic structure, microbial control, latitudinal gradients.

Juergen Kaselowsky
Forschungsinstitut und Naturmuseum Senckenberg, Sektion Marine Evertebraten III, Senckenberganlage 25, D-60325 Frankfurt, Germany

Shunsuke F. Mawatari
Division of Biological Sciences, Graduate School of Science, Hokkaido University, Sapporo, 060-0810 Japan

Gero Hillmer
Geologisch-Paläontologisches Institut und Museum, Bundesstrasse 55, D-20146 Hamburg, Germany

The role of microorganisms in shaping developmental and ecological processes in marine invertebrate communities has been largely overlooked. Marine biologists have focused almost entirely on macroscopic competitors and predators when assessing influences on sessile invertebrate communities and on the morphological patterns of individual colonies. For the phylum Bryozoa, numerous studies have been conducted on settlement patterns on bivalve shells, the latter being a perfect example of an isolated habitat island. On the other hand, the role of microbial mats and biofilms with regard to bivalve shells remains to be studied.

From May to July 2000, several hundred detached and living bivalve shells of various species have been collected at stations situated in Hokkaido, Honshu and Okinawa Island in Japan; furthermore, we collected in different sites in the New Zealand Region. In both countries, we have thus covered habitats from subtropical /marginal tropical to the cool temperate. This study is part of a larger project funded by research agencies in Germany, Japan, and New Zealand, on latitudinal gradients, and the role of bryozoans in (paleo)environmental and (paleo-)climatical deductions. It is our fundamental premise that morphology of the bryozoan colonies and species diversity are closely related to interaction with biomats. These microbial communities are known to react sensitively to temperature, light and other ecological factors that are in turn influenced by the respecitve geographical latitude.

We have quantified three bryozoan microhabitats on bivalve shells that are outlined by different intensities of microbial settlement: the convex outer valve, the concave inner valve, and the sheltered settlement space under the teeth and sockets.

Being a rather simple world when compared to the fractal surfaces geometries of rock substrates, the shell samples rendered it possible to find distinctive modern analogs to fossil bryozoan communities from subtropical to cool-temperate that so far have all been defined as temperate.

Bryozoan mass accumulation on tropical latitudes: the Eocene Castle Hayne Limestone, North Carolina, USA

Miklós Kázmér
Department of Paleontology, Eötvös University, H-1083 Budapest, Ludovika tér 2, Hungary

David Campbell
Biology Department, Saint Mary's College of Maryland, 18952 E. Fisher Road, St. Mary's City, MD 20686-3001, U. S. A.

István Fórizs
Geochemical Research Laboratory, Hungarian Academy of Sciences, H-1112 Budapest, Budaörsi út 45, Hungary

Steven J. Hageman
Department of Geology, Appalachian State University, Boone, North Carolina 28608, USA

Carbonate sediments deposited in Eocene tropical environments usually abound in Nummulites banks, red algal accumulations and sometimes in hermatypic corals. The east coast of North America enjoyed tropical climate in the Eocene, still none of these organisms are found in the Castle Hayne Formation of the Carolinas. This peculiar rock is dominated by species-rich bryozoan fauna associated with molluscs, solitary corals, echinoids, and brachiopods (bryomol association). The best-known bryomol limestones occur in the Eocene to Recent succession of the South Australian shelf and slope: there is well-documented evidence that these are products of cool-water currents of polar origin. We studied faunal composition, carbonate microfacies, and stable isotope composition of the limestone in the Castle Hayne Formation and found little evidence for cool-water sedimentation. Oxygen isotope composition of whole rock samples displays significant negative shift compared to the signal of temperate bryozoan carbonates in New Zealand suggesting warm water temperature.

What produced a typical bryomol carbonate of cool-water look on tropical latitudes? The flow of the Gulf Stream passing along the east coast of America was adjoined by the flow of the Suwannee Stream - passing from the Gulf of Mexico to the Atlantic across the neck of Florida - during Tertiary sea-level highstands. Barrages extending into the current (e.g. Cape Fear) caused significant turbulence and eddies. The subsequent upwelling yielded high organic productivity, suppressing the growth of organisms adapted to oligotrophic seas (larger foraminifers, algae, hermatypic corals), while causing gigantism among well-fed molluscs. Phosphate crusts are evidence for condensed sedimentation caused by rapid currents. When sea-level fall weakened or stopped the Suwannee Stream, a rich benthic fauna was formed and preserved. A similar, turbulent current regime has been documented in detail for the Miocene phosphate-rich beds of the Atlantic shelf. A similar present-day environment extends below the warm Agulhas Stream offshore South Africa: it helps to develop a disturbed environment with bryomol sedimentation. We suggest that the bryomol Castle Hayne Limestone is an azonal carbonate deposit within the tropical climate zone, displaying cool temperate characters due to local oceanographic conditions.

Functional morphology of maculae in a giant ramose trepostome bryozoan from the Permian of Greenland.

Marcus M. Key, Jr.
Department of Geology, Dickinson College, Carlisle, PA 17013-2896, USA

Lena Thrane (née Madsen)
Baker Atlas Geoscience, Jorcks Passage, Opg. A, 4. DK-1162 Copenhagen K, Denmark

Julie A. Collins
Department of Geology, Dickinson College, Carlisle, PA 17013-2896, USA

Colony-wide feeding currents are a common feature of bryozoan colonies with erect robust radial (i.e., ramose) branches. These feeding currents are centered around excurrent chimneys that expel previously filtered water away from the colony surface. Maculae in fossils have been interpreted by previous workers as sites of excurrent chimneys. The need for colony-wide feeding currents should be greater in colonies with more robust radial branches due to their greater and flatter surface area. This situation is magnified in a giant colony branch of Tabulipora from the Early Permian Kim Fjelde Formation in North Greenland. One cylindrical branch of this colony has a diameter of 37.5 mm. Twenty serial tangential peels were made through the 8 mm thick exozone. The peels intersected two stellate maculae as defined by contiguous exilazooecia. Macular spacing, size, and shape as well as the number and length of channels feeding the maculae were measured to see how they vary through the exozone in response to increasing branch size.

Results indicate that in this colony branch, macular spacing, size, and shape are a function of branch diameter. As the branch grows in circumference, the spacing and size of the maculae increase, and the maculae become more stellate with more and longer channels. This indicates that macular excurrent chimneys are dynamic in their position, size, and shape in response to changing hydrodynamics of colony-wide currents on a growing branch of a ramose colony.

The dynamic nature of macular excurrent chimneys is further demonstrated by an abrupt morphological change in the outer exozone. Macular spacing, size, and shape all reach maximum values in both maculae from 6.51 mm to 7.11 mm from the endozone. They then generally decrease toward the colony surface. This indicates something fundamental is changing in the exozone in this depth range. It is probable that the initiation of a new macula causes this effect, as the sizes of both maculae peak and then decline toward the colony surface. In response to this, the macular exilazooecia transform ontogenetically into autozooecia, pass into the intermacular areas, and are not replaced by new exilazooecia.

There is no evidence in the peels of a new macula developing in the exozone at this depth in the endozone. This may reflect that the new macula is on an adjacent part of the exozone and not in the block of exozone sampled in this study. The fact that macular size decreases and does not stay constant at some optimum size suggests that some of the incurrent autozooecia supplying the previous maculae have been pirated by the new macula (sensu stream piracy). This suggests that unless new macular chimneys are added and/or pre-existing ones expand in size, the feeding efficiency of the colony will decrease as the colony branch grows in circumference.

Bryozoa of the high Arctic fjord.

Piotr Kuklinski
Institute of Oceanology, Polish Academy of Science, ul. Powstancow Warszawy 55, Sopot 81-712, Poland

Kongsfjorden is placed on 79°N and 12E° on western coast of Spitsbergen, the biggest island of Svalbard Archipelago. It is 26,1 km long and on average 8km wide. Maximal depth of the fjord is 428 m, where the average depth is 141 m. Water masses of Kongsfjorden are influenced by warm West Spitsbergen Current (branch of Norwegian Current) and cold masses of Sorkap Current (originated from Arctic Ocean). To collect the samples two techniques have been used: grab and SCUBA diving. Stations ranged from 4 to 258 m depth. 89 taxa were recognized where 69 were determined to species, 17 to genus and 3 to family. Among all recognized species 10 of them were recorded first time to Svalbard waters. Data are analysed on the background of salinity, temperature, sedimentation rate, and bottom morphology. Species composition depend very much on depth of the station, what confirm MDS (multidimensional scaling) and cluster analysis. Shallow bryozoan communities are more abundant than the deep ones. Biodiversity increase with the depth. Among the most abundant were Celleporella hyalina, Hippothoa divaricata var. arctica, Harmeria scutulata, Tegella arctica and Tubulipora flabellaris. Dominant in the fjord were Electra crustulenta var. arctica, Cylindroporella tubulosa, Celleporella hyalina, Callopora craticula and Tegella arctica.

How many bryozoans? - Bryozoan numbers and fossilization rates: implications of an order-of-magnitude calculation.

Jennifer A. Lane and Roger J. Cuffey
Department of Geosciences (412 Deike Bldg.), Penn State University University Park, PA 16802, USA

Order-of-magnitude calculations are simple arithmetic manipulations of crude measures of large-scale parameters in order to approximate global trends, particularly to help guide societal policy makers. Such calculations can also roughly estimate certain scientifically interesting aspects of bryozoans, specifically the total numbers of living and fossil colonies, and their overall rate of fossilization. The dimensions of the earth allow estimation of the surface areas where most present-day bryozoans live (continental shelves, with reefs, shell beds, and meadows), and where most fossil bryozoans are preserved (cratons, orogenic belts, coastal wedges). Average thicknesses of those latter permit calculation of their total volumes. Specimen counts and field examinations indicate typical concentrations of bryozoan colonies in those tectonic regions during different eras, and in modern environments. These concentrations combined with the previous volumes suggest the total numbers for the globe: roughly 1016 living bryozoan colonies, 1022 - 1023 colonies preserved in the fossil record, 1014 fossilized each year, implying that somewhere on the order of 1 in 100 colonies enters the fossil record.

Four species of epiphytic bryozoans on Sargassum from Peace Island North Taiwan.

Liu Hung-Chun and Jane E. Lewis
Seaweed Biogeography Laboratory, Institute of Marine Biology, National Taiwan Ocean University, 2 Peining Road, Keelung-202, Taiwan

This poster reports on bryozoan fauna associated with the seaweed Sargassum sandei from Peace Island (North Taiwan). Sargassum plants were observed in July and August, 2000. All plants with epiphytes were collected and observed macroscopically and with SEM. Four epiphytic species were found: Jellyella tuberculata, Scrupocellaria maderensis, Catenicella triangulifera and Watersipora subtorquata (Order Cheilostomatida). These are all new records for Taiwan. Short descriptions of each species and SEM photographs are presented. This research project was supported by a Republic of China National Science Council summer student research project grant.

Genetic delineation of higher taxa in Phylactolaemate bryozoans.

Michael Lore

Department of Biological Sciences, Wright State University, Dayton, OH 45435, USA

This study addresses the systematic relations among the five known families of freshwater bryozoans (Ectoprocta: Class Phylactolaemata). The group lends itself particularly well to genetic work because it is extremely diverse yet small and well defined. Bryozoans have been previously classified only by their external morphology, leaving certain phylogenetic and evolutionary relationships somewhat speculative.

The approach used here is to focus on sequences coding for ribosomal RNA, specifically the 18s and ITS-1 regions. Much ofthe material examined was collected during a survey of British phylactolaemate bryozoans by Okamura, Wood, and Lore in the summer of 2000. Additional material, such as the lophopodid species, have come from Europe and North America.

Results (still being analyzed) reveal strongly conserved genomes within the 18s region. The family status of Hyalinella punctata is expected to be clarified, along with the structure of the genus Plumatella and relations among the nontubular taxa.

Septopora (Order Fenestrida) in Upper Mississippian (Chesterian) rocks of the eastern United States.

Frank K. McKinney
Department of Geology, Appalachian State University, Boone, NC 28608 USA

The fenestrate bryozoan Septopora is widespread but only locally common in diverse Chesterian (Upper Mississippian) quiet water carbonate platform and basin deposits in the eastern United States. The genus is characterized by pinnate, commonly planar colonies with two rows of autozooecia per branch; subparallel main branches with short, fused lateral branches rather than barren dissepiments; and by hemispherical polymorphs (cyclozooecia) of unknown function opening or reverse sides of junctions of main and lateral branches. Some have single small hemispherical depressions, which may also be cyclozooecia, between autozooecial apertures on frontal branch surfaces.

Species characteristics include distance between branch centers, diameter of the distal tube (equivalent to apertural diameter on the branche surface), apertural spacing along rows, fenestrule size, and size of cyclozooecia. S. subquadrans Ulrich is the most abundant, widespread and apparently long-ranged species. Other species, including the type species, S. cestriensis Prout, are distinct but less abundant or temporally long-ranging.

The ctenostome collar - an enigmatic structure.

Marjorie J. McKinney
Department of Geology, Appalachian State University, Boone, NC 28608, USA

Ruth A. Dewel
Department of Biology, Appalachian State University, Boone, NC 28608, USA

Setigerous or pleated collars are regarded as characteristic of ctenostome bryozoans, yet little has been recorded about their form, microstructure, behavior, or possible taxonomic significance.

Observations of living ctenostomes in Rovinj, Croatia and Morehead City, North Carolina and a study of the ctenostome literature suggest that there are four basic collar forms. Two types (Forms 1 and 2) have the appearance of a short, unflared, simple cuff surrounding the basal portion of the lophophore. In both types, the distal collar margin is smooth or nearly so. Form 1 seems to be a simple membrane and Form 2 is conspicuously setigerous with setae sometimes extending slightly above the distal margin of the collar. Form 3 is short or may extend to approximately one-third the length of the lophophore; it may be flared and has a serrated distal margin in which the membrane may be deeply scalloped between the setae. Form 4 is distinctly flared and its distal margin may extend to just below the distal portion of the tentacles.

In thin-section, the Form 4 collar is seen to be twisted within the vestibule. Inside the vestibule, the setae, square to rectangular in cross-section, are peripheral to the connecting membranes which are tightly coiled within the structure. In living zooids with Form 4 collars, the collars begin to twist when the lophophore begins to retract.

The function of collars as zooecial closures is generally acknowledged. Oddly, in many zooecia observed in this study and in a number in the literature, the collar remains partially to entirely extended in active zooids and collars in some species may remain extended in degenerate zooids. Observations of living ctenostomes suggest that collars may also serve to reduce the amount of debris encountered by the lophophores. Surfaces of ctenostome zooids tend to accumulate sediment and sticky films. When the collar protrudes, it pushes this surficial debris aside, preventing the lophophore from becoming fouled.

It has been suggested that collars are developed to a different degree in different families. In this study, the forms recognized above do seem to characterize certain traditionally recognized families. However, at a higher taxonomic level, both carnosan and stoloniferan ctenostomes exhibit a range of forms.

The population genetic structure of three introduced bryozoans in southern Australia - unravelling the role of shipping in dispersal.

Joshua Mackie and Michael Keough
Department of Zoology, University of Melbourne, Victoria 3010, Australia

Les Christidis
DNA Lab, Museum of Victoria, Melbourne, Victoria 3001, Australia

The occurrence of a number of species in ports and harbours on different continents is evidence that shipping facilitates dispersal. We studied the population genetics of three cheilostomes which are thought to have been introduced by shipping to Australia. The first two species, Bugula neritina and Watersipora subtorquata, are widespread in southern Australia, while the third species, W. arcuata, is found around Perth, Adelaide and Sydney but is absent from more southerly localities. To determine whether introductions stem from the same ancestral population, and whether urban centres have received the same introductions, we compared genetic variation in mitochondrial CO1 sequences from colonies sampled at disjunct locations. W. subtorquata and B. neritina sequences had no significant intraspecific variation suggesting colonisation from a single genetic source. W. arcuata sequences were polymorphic and 11 haplotypes were identified from 30 sequences. These haplotypes can be can be assigned to three diverged lineages which do not show geographical structuring. This situation supports the pattern expected if ships have drawn haplotypes from multiple isolated populations and deposited them randomly with respect to location. To provide a clearer insight into how the mode of introduction affects variation the impact of natural dispersal processes needs to be understood. We discuss the findings for these introduced species with reference to genealogical patterns found for south eastern Australian populations of the endemic species Mucropetraliella ellerii.

Results of a freshwater bryozoan survey in the Pacific Northwestern United States.

Terrence Marsh
Department of Biology, North Central College, Naperville, IL 60566-7063, USA

Timothy S. Wood
Department of Biological Sciences, Wright State University, Dayton, OH 45435, USA

Although freshwater bryozoans have been reasonably well documented in scattered regions of eastern North America, the areas west of Ontario and the Mississippi River are relatively unexplored. This study represents the first known attempt to gather statewide information on bryozoans in the Pacific Northwestern United States. For four weeks in July and August 1998, we traveled throughout Oregon and Washington as well as part of adjacent Idaho collecting colonies and sieving shoreline debris for statoblasts. We narcotized live colonies then preserved them in 70% ethanol. We stored statoblasts, dried, in sealed plastic bags. Many of the species we encountered are also common in eastern North America, including Cristatella mucedo, Fredericella browni, F. indica, Hyalinella punctata, Paludicella articulata, Pectinatella magnifica, Plumatella casmiana, P. emarginata, P. nitens, P. rugosa, and P. similirepens. One surprise was Fredericella sultana, common in Europe but until now unknown in North America, which we found at Garrison Lake, in Curry County, Oregon. We found statoblasts of Lophopodella carteri, which was previously unknown west of Illinois, in three localities in this study. Also unexpected was the widespread occurrence of Stephanella hina, a species well known in western Asia and previously known from only a few populations in New England. Notably absent from our collections was Plumatella reticulata, one of the most common species in the east and Midwest. Also missing were Plumatella fungosa, P. vaihiriae, and the ctenostome, Pottsiella erecta.

Species of Microporella (Bryozoa, Cheilostomata, Ascophora) with personate ovicells found from the bryozoan collection in the Natural History Museum, London.

Shunsuke F. Mawatari and Sayumi Shirakawa
Division of Biological Sciences, Graduate School of Science, Hokkaido University, Sapporo, 060-0810, Japan

Mary E. Spencer Jones
Department of Zoology, The Natural History Museum, Cromwell Road, London SW7 5BD, UK

Five species of Microporella (Bryozoa, Cheilostomata, Ascophora) with personate ovicells, i.e. Microporella n. sp. A, Microporella n. sp. B, Microporella orientalis, Microporella personata, and Microporella harmeri were described or redescribed from the collection of the Natural History Museum, London, UK. Microporella n. sp. A is characterized by its large avicularia almost touching the ascopore, long and setiform mandibles, and the lower lip of ovicells which consists of two triangle plates fusing over the ascopore like an overpass. Microporella n. sp. B is distinguished by its avicularia located distant from the ascopore by about the length of orifice, directed almost horizontally, and the ovicells with complete lower lip in which three outgrowths fuse to conceal the ascopore. Microporella personata Busk, 1854 and Microporella orientalis Harmer, 1957 are redescribed with particular regards to the length and form of mandibles, the detailed morphology of the lower lips of ovicells, the location of ascopore and avicularia, and the size of frontal pores. Microporella harmeri Hayward, 1988 was redescribed as a unique species with two types of mandibles in one colony; one is setiform, and the other is lanceolate with broad wings asymmetrically.

A (very) preliminary report on the biodiversity of the bryozoan faunas from the Plio-Pleistocene of the Greek island of Rhodes.

Pierre Moissette
Université de Lyon I, UFR Sciences de la Terre, 27 Bd du 11 novembre, 69622 Villeurbanne Cedex, France

Nils Spjeldnaes
Universitet i Oslo, Institutt for Geologi, BOKS 1047, Blindern, 0316 Oslo, Norway

Bryozoans are very abundant in the Upper Pliocene to Lower Pleistocene marine sediments of Rhodes: sands, sandstones, marls, and limestones. With 250 species already identified their biodiversity is also very high, especially when compared with the about 300 potentially fossilizable (entirely calcified) species described until now in the whole Recent Mediterranean. Even when taking into account the time span involved (about 1 Ma) the diversity of the bryozoans is still remarkable, especially when considering that in the Plio-Pleistocene of Rhodes only some habitats and depth ranges (from 0 to about 600 m) are represented.

On the basis of their (palaeo)geographic distributions, the species occurring in the Plio-Pleistocene deposits of Rhodes may be classified into several groups. The largest one consists of species with an Atlantic range (either temperate-boreal or warm-temperate). Smaller groups are the Mediterranean endemics, the species with almost cosmopolitan distribution, and the rare Indo-Pacific species. Two other groups are however lacking from the present-day Mediterranean: the warm-water, tropical species and the cold-water species of boreal-Atlantic origin.

The presence of these later two groups and the high biodiversity of the bryozoan faunas of Rhodes could be due to a number of factors. First, temperature stratification and water circulation may have been different at the end of the Pliocene and the beginning of the Pleistocene allowing some species to enter the Mediterranean, and even the eastern Mediterranean, from the colder North Atlantic. Another possibility is that the warmer climate of the relatively isolated Aegean region allowed tropical species to survive and even thrive in some areas in spite of cold-water influx, either from the Atlantic or from upwelling currents.

The organization of the Plio-Pleistocene marine deposits of the island of Rhodes also reflects several cycles of regression and transgression due to intense tectonic movements and glacio-eustatic variations. Together with frequent temperature oscillations this could have made more habitats available for bryozoans (e.g. deep-water corals, microbial calcareous crusts and mounds, rapidly cemented beachrocks, etc.).

High faunal turnovers (extinctions, originations and migrations) driven by a combination of tectonic, climatic and oceanographic environmental changes in this part of the Mediterranean may thus explain most of the observed unusual high biodiversity.

The effects of microbial growth on Bryozoa in a 330 M.Y. old hydrothermal vent system (Big Cove Formation, Codroy Group, Port Au Port Peninsula), Western Newfoundland, Canada.

Penny A. Morris
Dept. Nat. Science, University of Houston-Downtown, Houston, TX 77002, USA

Peter H. von Bitter
Dept. Palaeobiology, Royal Ontario Museum, Toronto, Canada M5S 2C6

Paul E. Schenk
Dept. Earth Sciences, Dalhousie University, Halifax, Canada (deceased)

330 million years ago, an Early Carboniferous vent system developed in rift margin settings in western Newfoundland and resulted in bryozoan/carbonate buildups over a fractured Ordovician limestone 'basement'. The carbonate buildups or mounds vary in thickness from a few centimetres to several decametres. They are characterized by extensive deposits of microbial origin, including abundant bacterial 'fingers', 'oatmeal-like' textures, and layered calcium carbonate and pyrite. These deposits coated monospecific populations of bryozoans, brachiopods, and probable vestimentiferan tube worms. The microbial products encrusted all invertebrates to varying degrees, but particularly affected the bryozoan population.

An Early Carboniferous bryozoan that is similar to ?Anisotrypa, frequently forms the nucleus for ball-like microbial deposits are composed of alternating layers of bryozoans and microbial calcium carbonate that seldom exceed 2 mm in size. Some of the larger spheres contain as many as ten layers, each layer varying in thickness from .1 to .8 mm. The bryozoan colonies apparently cannot regenerate if the microbial layer exceeds .8 mm. FEG-SEM images indicate that the microbial carbonate is morphologically distinct from the abiotic calcium carbonate as the former is extremely fine-grained, and appears to weather more easily than the latter. In addition, the microbial carbonate is layered, resembling piled tree logs.

The existence of a vent-inhabiting bryozoan is unique in both the fossil and modern environment. The bryozoan is characterized by anomalies that make it difficult to assign to a specific genus or species, although it possesses some features that align it with Anisotrypa. For instance, Anisotrypa characteristics include short, inclined zooecia, sparsely developed perforated diaphragms, and no ring septa. Other anomalies, such as the small colony size, and the general absence of a mature zone may be attributed to the stressed environment. Of course, all of these anomalies, including the habitation of a deep water vent community may indicate that this is an undescribed genus.

The presence of a variety of microbial forms such as 'fingers', oatmeal-like flakes, and ball or sphere-like growths is reminiscent of a modern Bahamian environment, but ?Anisotrypa sp. was part of a deeper water vent community that is characterized by abundant evidence of microbial activity, restricted invertebrate diversity, and sulfide deposits that include pyrite, sphalerite and galena. The extreme environment resulted in restricted growth and development of the bryozoan ?Anisotrypa sp. The bryozoan survived marginally in this stressed environment.

Bryozoa from oceanic south eastern Pacific islands: diversity and zoogeography.

Hugo I. Moyano G. Departamento de Zoología, Universidad de Concepción, Casilla 160-C, Concepción, Chile

As part of extense and lineal submarine ridges within the Nazca plate there are several relative small very isolated islands like Easter (Pascua) and Salas y Gómez , and archipelagos like Juan Fernández (Robinson Crusoe, Alexander Selkirk and Santa Clara) and Las Desventuradas (San Félix and San Ambrosio). All of them are situated out of the Humboldt cold current being affected by tropical and subtropical south eastern pacific waters.

This oceanographic and geographic situation allows to predict that they should have a different bryozoological fauna in comparison with the Chilean-Peruvian one from ca. 6°S to 42°S along the western Pacific coast of South America.. The hitherto published reports on the bryozoans of these remote islands clearly indicate that Easter island (20 fams., 27 gen. 37 spp) and Juan Fernández archipelago (22 fams., 24 gen., 43 spp) constitute two tropical and subtropical bryozoogeographical provinces respectively with little or none zoogeographical connections with the Chilean-Peruvian province.

The current study of some bryozoan samples collected in October 1999 in intertidal places around Easter island yielded a new record for Jellyella eburnea (Hincks) growing on plastic debris. A similar study carried out on samples gathered at 50-100 m depth around the smallest Salas y Gómez island (only 2.5 km2) has already yielded 20 species. Some of them belong so far to unknown families and genera in Chilean waters, namely Gigantopora, Mollia and Rhynchozoon. At least one species Microporella orientalis Harmer extends its known range from the western tropical Pacific to the eastern one. It is highly likely that other species when fully determined confirm the extension of the Indopacific bryozoan fauna at least to islands like Easter and Salas y Gómez and submarine mounts lying on the western margin of the Nazca plate.

A new expedition (October , 2000) to the less remote Chilean Oceanic islands, e.g. Las Desventuradas and Juan Fernández archipelago, will allow to collect new bryozoan samples. The greatest interest in the results of this expedition has to do with Las Desventuradas real zoogeographical status because Russian studies of fishes along a series of guyots of the Salas y Gómez and Nazca submarine cordilleras indicate the extension of the Indopacific marine fauna until near Las Desventuradas islands. A Chilean study on the same subject arrives to a similar conclusion. If this is a general situation involving vertebrate and invertebrate biota it is then highly probable that some Indopacific bryozoans will be present on the shelves of these islands.

The aim of this presentation is to communicate the bryozoan diversity and zoogeography that the current studies will yield by the middle of 2001.

Bryozoa cyclostomatida from remote south eastern Pacific islands: a pictorial review.

Hugo I. Moyano G.
Departamento de Zoología, Universidad de Concepción, Casilla 160-C, Concepción, Chile

The present status of knowledge of cyclostomatous bryozoans known in southern hemisphere so far is still precarious. It is so both in the zoogeographical and taxonomic points of view. Cyclostomatous bryozoan knowledge from very isolated lands on the vastness of the eastern south Pacific ocean is still lesser. So, this poster will show some aspects of the diversity and zoogeography of the remote cyclostome bryozoan faunas by means of graphics and pictures.

The known cyclostomatous bryozoa from Juan Fernández archipelago include 13 species in 9 genera and 7 families. Apparently the most common and abundant species are Frondipora masatierrensis Moyano and Annectocyma cf. major (Johnston). Other taxa principally include three species of Crisia, two of Diastopora, two of Tubulipora and the so-called cosmopolite Idmidronea atlantica (Forbes).

At present 12 spp in 8 genera and 7 families have been collected from Easter Island. These principally include two species of Crisia, two of Diastopora, two of Idmidronea and the so-called "panpacific" Crisina radians Lamarck.

The current study of the bryozoans samples collected from Salas y Gómez island has already produced four species: Crisia sp., a Crisina radians-like species, Diastopora ridleyi and Annectocyma cf. major The first three are also present in Easter Island and the last one in Juan Fernández.

A Moscovian (Carboniferous) bryozoan bioherm from Svalbard.

Hans Arne Nakrem
Paleontologisk museum, Sars' gt 1, N-0562 Oslo, Norway

Upper Palaeozoic bioherms and reefs formed by fenestellid bryozoans are known from several areas. Fieldwork in Spitsbergen in the early 1990s revealed bryozoan bioherms approximately 20 m thick and 200 m wide within the Minkinfjellet Formation in central Bünsow Land. These structures are dated by conodonts and fusulinids to be of (late) Moscovian age. Bioherms of similar age are also reported from North Greenland.

The bioherm core facies is composed primarily of a light grey, massive, fenestrate bryozoan wackestone. Complex stromatactoid cavity systems are often roofed by large fenestellid fronds. Inferred marine cements line cavity walls, and replacement by dolomite obscure some micro-detail in the bryozoan skeletons.

The bioherms are dominated by fenestellid bryozoans, with many genera represented (Flexifenestella, Rectifenestella, Alternifenestella, Penniretepora, Ptylopora, Acanthocladia, Polypora and Polyporella). Cryptostomes are very rare, whereas many fenestellid fronds serve as substrate for fistuliporid cystoporates, Tubiphytes, and small encrusting foraminiferans. Algal components are generally absent in the bioherms.

The crinoidal grainstone topping the bioherm contains a different bryozoan fauna, with species of Goniocladia, Rhombotrypella, Archimedes, and Ascopora, in addition to fragmented fenestellids.

Origin of the multiserial forms in evolution of Cheilostomata.

E.A. Nikulina
Paleontological Institute of Russian Academy of Sciences, Moscow, 117868, Russia

First Cheilostomata known from the Late Jurassic had uniserial colonies encrusting a substratum. Besides such forms multiserial colonies appeared in the Early Cretaceous. They were represented by round encrusting sheets consisting of hexagonally packed zooids. Since the latest Cretaceous multiserial forms dominate. The study of development of extant bryozoans helps to clarify the origin of multiserial forms and reasons of their dominance. The main difference in development of uniserial and multiserial colonies is a sequence in which the buds of zooids arise. There can be two variants, proxipetal and distopetal budding.

In bryozoans with proxipetal budding distal bud develops firstly. After that lateral buds of zooid develop. Buds arise in series from the distal part of zooids to the proximal one. Due to such budding in zooidal rows lengthening precedes branching. It leads to uniserial organization.

On the contrary, in a case of distopetal budding buds arise from the proximal to distal part of zooid. Thus, the round multiserial colonies are formed, and possibility of derivation of single chains of zooids is excluded since their branching precedes lengthening. The comparison of morphological features of extant bryozoans with fossils has shown that the origin of multiserial colonies from uniserial ones in the Early Cretaceous is explained by change of budding sequence. The transition from proxipetal budding to distopetal was caused by shifting time of buds origin to earlier stages of zooidal morphgenesis that proceeds from proximal part of zooid distally.

Such heterocrony results in abbreviation of period between appearance of the subsequent generations of zoods and, finally to increasing growth rate of a colony. The growth rate has essential selective value in competition for biotic space, in defense from overgrowing and damages by predators. Probably, the time shift of buds origin to earlier stages of a zooidal morphgenesis is product of natural selection for growth acceleration. Thus, the sequence of budding has changed from proxipetal to distopetal. As result multiserial forms originated. It is possible to reach the conclusion that multiserial organization can be a by-product of evolution to growth acceleration. At the same time such innovation in itself has appeared useful. It formed the basis for further morphological evolution of Cheilostomata. In the Late Cretaceous and Cenozoic there were modifications of multiserial sheets, viz. multilamellar, erect unilamellar, bilamellar, cylindrical colonies appeared.

The conservation of Lophopus crystallinus in the UK.

Aaron O’Dea
14 Ninetree Hill, Kingsdown, Bristol BS1 3SQ, UK

Ian Middlebrook
Invertebrate Conservation Officer, Butterfly Conservation, Manor Yard, Wareham BH20 5QP, UK

The freshwater bryozoan Lophopus crystallinus is classified as rare in Britain and has only been recorded from four sites in the last 30 years. It is one of 170 priority invertebrate species for which Species Action Plans (SAPs) have been published as part of the UK Biodiversity Action Plan. The plan for Lophopus crystallinus sets out overall objectives of maintaining all long-term populations and facilitating a natural increase in the number of populations. This project will begin long term surveying of select localities within the UK to try to establish the extent of remaining populations, will aim to identify the potential threats to the species and provide data for habitat management. The presentation of this poster aims to promote the study of Lophopus in Britain and invites information and discussion of the status of Lophopus populations worldwide.

Brood chambers in cribrimorphs evolved by fusion of costae: further arguments.

Andrew N. Ostrovsky
Department of Invertebrate Zoology, Faculty of Biology & Soil Science, St. Petersburg State University, Universitetskaja nab. 7/9, St. Petersburg, 199034, Russia

The hypothesis that ovicells in cribrimorph cheilostomatides originated by fusion of costae was first proposed by Lang (1921), although as early as 1902 the resemblance in the development of ovicell and autozooidal frontal shield was stressed by Harmer in Euthyroides episcopalis. Different authors added the list of arguments in favour of Lang’s suggestion: Boardman et al. (1983) illustrated a confluence of the ooecial cavity with the body cavity of daughter autozooid in Figularia figularis. Bishop and Househam (1987) showed that in Puellina the ectooecium of the ovicell and the frontal wall of the distal autozooid are continuous. Also a continuity of the medial suture of ectooecium and frontal shield surface is seen on illustrations of Lang (1921) and Larwood (1962) in some cribrimorphs. In ovicells of Cribrilina annulata which superficially appear to be whole, the bilobate structure of ooecial fold and medial suture of entooecim was described (Ostrovsky 1998). In this species, as well as in Puellina harmeri, the "radial" pattern of ectooecial calcification was also recorded (Ostrovsky 1998, Ristedt 1985). Finally, almost all of the authors mentioned above noted great similarity in an appearance of brood chambers and spinocyst of some cribrimorphs.

Some new evidence was recently obtained in favour of Lang’s suggestion. In Puellina hincksi and P. radiata pelmatidia were found on costae as well as ooecial surface. Also there is a closed horizontal slit in the ooecial fold in both species examined that might be a rudimentary passage between a cavity of the ovicell and epistege in ancestral cribrimorphs. By this means, evolution of brood chambers in this clade might be compared with that known in membraniporid Tendra zostericola posessing acanthostegous brood chambers.

Phylactolaemate bryozoans are hosts of a new class of myxozoans, including the causative agent of salmonid proliferative kidney disease.

Beth Okamura
School of Animal and Microbial Sciences, University of Reading, Reading RG6 6AJ, UK

Elizabeth U. Canning and Cort L. Anderson
Department of Biology, Imperial College of Science, Technology and Medicine, London SW7 2AZ, UK

The Myxozoa is an enigmatic group of endoparasites distinguished by a long history of phylogenetic and taxonomic uncertainty. Recently two myxozoan species have been discovered freely floating within the coelomic cavity of phylactolaemates where they proliferate as saclike bodies in which infective spores develop. Comparisons of morphologies and life cycles have revealed major differences between these bryozoan parasites and the better known myxozoan parasites of fish and worms. Phylogenetic analyses of 18S rDNA sequences identify two clades within the Myxozoa that diverged early in the evolution of the group. Insights derived from developmental and phylogenetic study suggest that bryozoans may have been ancestral hosts of myxozoans and provide the basis for identifying a new class of myxozoans, the Malacosporea. In addition, discovery of the bryozoan parasite, Tetracapsula bryosalmonae, has identified the source of the causative agent of Proliferative Kidney Disease, a devastating disease of salmonid fisheries resulting from accidental infection by a previously unknown myxozoan.

Natural products from North Sea organisms: bryozoans and associated bacteria.

L. Peters, D. Akkermann, G.M. König, and A.D. Wright
Institut für Pharmazeutische Biologie, Universität Bonn, Nußallee 6, 53115 Bonn, Germany

R. Pukall and E. Stackebrandt
DSMZ-Deutsche Sammlung von Mikroorganismen und Zellkulturen, Mascheroder Weg 1b, 38124 Braunschweig, Germany

Marine invertebrates and bacteria associated with them are becoming a new resource for marine natural products and drug research. One of the most promising anti-cancer compounds from marine organisms is the polyketide bryostatin 1 derived from the cheilostome bryozoan Bugula neritina.

The current study focuses firstly on the isolation and systematic classification of bacteria associated with bryozoans and tunicates, sampled from different places in the North Sea near Helgoland, and secondly on the analysis of the secondary metabolites produced by these macro- and microorganisms.

Investigation of approximately 15 different bryozoans and tunicates has shown that extracts of two bryozoans, Electra pilosa and Flustra foliacea, caused high mortality in the Artemia salina assay. Chemical analysis of Flustra foliacea extract by GC-MS revealed the presence of nine alkaloids. Two of these componds were found to be new natural products.

More than 250 bacterial strains were isolated from different North Sea macroorganisms and cultured. Extracts of both the liquid culture medium and the bacterial cells were prepared to screen for secondary metabolite production and biological activities. Three strains of Pseudoalteromonas sp. and Psychroserpens spp. from Flustra foliacea were found to cause high mortality in the Artemia salina assay. Chemical analysis of Psychroserpens spp by HPLC-DAD showed the precence of approximately 5 compounds with UV-maxima in the range 280-300 nm. Currently, large scale cultivation of this bacterium is in progress, as well as further chemical and biological evaluation of a number of other strains (Vibrio spp., Shewanella spp., Pseudoalteromonas spp., Alteromonas spp., Aeromonas spp., Planococcus spp., Halomonas spp.) obtained from Flustra foliacea and Bugula plumosa.

Neurotoxin found in the freshwater bryozoan Lophopodella carteri (Ectoprocta: Phylactolaemata).

Nancy Peterson
Department of Chemistry, North Central College, Naperville IL 60566-77063, USA

Previous studies have shown that fish die in the presence of crushed Lophopodella carteri. However, the mechanism of action was not elucidated. Here, I report that L. carteri homogenate contains a neurotoxic component. Colonies of L. carteri were collected in Lake Shabbona in DeKalb County, Illinois, located at 41°44’45" N latitude and 88°51’30" W longitude. I homogenized the colonies in 10 mM phosphate buffer (pH 7.2) and centrifuged at 4000xg to precipitate cellular debris. Aliquots of the supernatant (protein concentration = 1.4 mg/ml) were stored at -80°C. I tested for neurotoxins by bath applying the homogenate to rat hippocampal slices while monitoring neuroactivity in the Schaffer Collateral-CA1 pathway using extracellular recording techniques. I found that the homogenate was neurotoxic with an IC50 = 6 ml for orthodromic responses and an IC50 = 10 mL for antidromic responses. Inhibition of orthodromic and antidromic responses leads me to hypothesize a nonsynaptic mode of action. The neurotoxic component apparently acts as an antagonist as noted by the lack of population spikes. Further, the inhibition was reversible. The neuronal response returned after removing the toxin. In an attempt to isolate the toxic component of the homogenate, I have begun purification of the toxin. Treatment of the homogenate to a boiling waterbath for 15 minutes does not reduce the neurotoxicity. Further, gel filtration (sephadex G-50) shows that the toxin has a molecular weight of less than 1500. These data would suggest that the toxin is not a protein, but a small molecule. This would be similar to bioactive molecules that have been found in some marine Bryozoa.

Molecular phylogeny of the ctenostomate genus Alcyonidium using 12S and 16S mitochondrial DNA genes.

Joanne S. Porter, Peter J. Hayward, Jean Leamon, Chris Beynon and David O.F. Skinbinski
School of Biological Sciences, University of Wales Swansea, Singleton Park, Swansea SA2 8PP Wales, UK

The genus Alcyonidium is highly speciose, and includes taxa which exhibit very different reproductive strategies. In this study, DNA sequence data was generated from mitochondrial DNA, for the 12S and 16S ribosomal genes. This data was used to construct phylogenetic trees, upon which characters such as reproductive strategy, colony form and preferred substrate were mapped. Patterns resulting from the analysis will be discussed with respect to convergent evolution of these characters and the possible role of microevolutionary forces in the evolution of the genus.

A survey of Ctenostome Bryozoa from the Antarctic, using a molecular approach.

Joanne S. Porter, Peter J. Hayward, Jean Leamon, Chris Beynon and David O.F. Skinbinski
School of Biological Sciences, University of Wales Swansea, Singleton Park, Swansea SA2 8PP Wales, UK

Few species of the genus Alcyonidium have been reported from Antarctica, the most interesting of which is a pelagic spherical colony recently reported by Peck et al. 1995. The bryozoan collections of the US ARP include numerous samples of species of Alcyonidium from the South Shetland Islands, Antarctic Peninsula and Ross Sea. These include a number of epibiotic taxa but the preponderance consist of large erect colonies with morphologies recalling those of the subtidal species of the Northern hemisphere. The specimens were sorted into colony morphotype and geographic region. DNA sequencing of mtDNA genes establishes the specific identity of each of the morphotypes, none of which shows any identity with the enigmatic pelagic species.

Diverse, interacting bryozoans encrusting a bivalve substratum in the Cretaceous (Maastrichtian) Prairie Bluff Chalk, west central Alabama, USA.

Susan K. Powers
Department of Geology, Appalachian State University, Boone, NC 28608, USA

Encrusting bryozoans are common on bivalve substrata in the Late Cretaceous (Maastrichtian) Prairie Bluff Chalk in west central Alabama. One right valve of the bivalve Picnodonte is abundantly encrusted by at least 15 species belonging to the cyclostome genera Annectocyma, Diplosolen, Eurystrotos, Idmonea, and Plagioecia and to the cheilostome genera Amphiblestrum, Aplousina, 'Balantiostoma', Castanopora, Cheethamia, 'Mystriopora', 'Ramphonotos', Stichomicropora, Tricephalopora, and Wilbertopora. Approximately 65% of the shell surface is covered by colonies of encrusting bryozoans. Most are small, but a species of Stichomicropora forms extensive, thinly calcified sheets. Colonies commonly are in contact with one another along their perimeters and frequently overlap. Encrusting bryozoans on the shell show various responses to proximity to neighbors, including outgrowths of smaller zooids that are directed towards the neighboring colony, growth of thicker over thinner colonies, and growth termination upon contact.

Hydrodynamic effects on colony form in marine bryozoans.

Marney C. Pratt
Department of Biology, Duke University, Durham, NC 27708, USA

Bryozoans can exhibit a wide variety of different colonial growth forms. These growth forms can roughly be divided into species that are erect or encrusting. I compared the effects of hydrodynamics on the growth and survival of an encrusting and an erect bryozoan. Membranipora membranacea has an encrusting growth form and is found almost exclusively on large flat macroalgae (such as kelps) in relatively high and low flow habitats. Bugula pacifica has an erect growth form and is generally found on hard substrata (such as docks or rocks) in relatively low flow habitats. These two species can overlap in habitat: both can be found on large macroalgae in low flow environments. Previous data suggest that Membranipora can capture more 20µm diameter particles than Bugula at both slow (2.5cm/s) and fast (10cm/s) flow velocities. However, it remains to be seen whether a higher particle capture success translates into faster growth and/or higher survival rates. I measured the growth (change in area) and survival rate of Membranipora and Bugula colonies in the field in a high and low flow habitat over a month and a half time period. Growth rate did not vary greatly between high and low flow habitats for either species, but survival rate did vary between species and between habitats. Membranipora had a higher survival rate than Bugula in both flow habitats, and both species had a higher survival rate in the slower flow habitat than in the higher flow habitat. These results suggest that hydrodynamics can have a large effect on survival of bryozoans based on their growth form.

The Bryozoans and Kamptozoa in cooling waterbodies of nuclear and thermal power plants.

Alexander Protasov and Olga O. Sinitsyna
Institute of Hydrobiology, Academy of Sciences of Ukraine, Kiev, 04210. Ukraine

There are many water bodies, used as cooling systems of Power Plants: lakes, artificial ponds, rivers, reservoirs. The raise of temperature of water on 8-10° are characteristic for this water bodies. Some species of Bryozoa: Plumatella fungosa Pallas, P. emarginata Allm., P. repens L, P. cosmiana Oka, Crystatella mucedo Cuvier, Fredericella sultana Blumenbach, Paludicella articulata and E chremb. are found in this water bodies in Ukraine, Poland, Russia. The unique species of freshwater Entoprocta, spontaneously introducing in reservoirs of Europe from Northern America Urnatella gracilis Leidy is found out also (Kanev Reservoir, Konin Lakes).

In zones of maximum temperature (30-37°) in cooling ponds of Ukraine and Poland the greatest development in discharge channels reached P. emarginata, the biomass it achieved 1,0-1,2 kg/m2. Colonies of this species are marked not only on usual substrata - stones, concrete, but also on dense sand in discharge channel of Patnow Power Plant (Poland) with a biomass 100 g/m2. The stone dams are very favourable biotope for development of Bryozoans. On stones of a dam in a cooling pond of Chernobyl NPP marked a biomass of P. emarginata more than 7 kg/m2. Is paradoxical looks that the greatest biomass 18 kg/m2 was marked in engineering systems of cooling of oil on one of stations of Ukraine (Krivorozhskaya TPP). Cristatella mucedo met on high water plants (Potamogeton) and other immersed substrata. In July, 2000 Cristatella mucedo in a huge amount (4500 colonies by a size 1-2 cm on 1 m2) were found out in intake channel of Konin Power Plant (Poland) on sandy bottom, stones, shells and other substrata.

Complicated spatial microstructure of colony of bryozoans, especially P. emarginata creates favourable conditions for shaping rather rich biocenosis, in which is marked about to 40 species of invertebrates from Oligochaeta, Ostracoda, Coelenterata, etc. Together with bryozoans met s. The number of it colony reaches 90 000 on m2, biomass reaches 37 g/m2 (Konin lakes, Poland). There are all foundations to suppose, that in distribution of this species in reservoirs of Europe a large value have discharge heated water of power stations, as the temperature range it live in reservoirs of Northern America (10-30°) is close to a temperature condition of cooling reservoirs of average Europe.

Thus, in cooling reservoirs there are conditions for successful development of Bryozoans and Kamptozoa shaping of complicated communities.

Colonization of bryozoans in natural and artificial algae.

Lais Vieira Ramalho
Condominio Pontal do Atalaia - Casas Brancas n.30, Praia Grande, Arraial do Cabo, Rio de Janeiro, Brazil

Ricardo Coutinho
Instituto de Estudos do Mar, Almirante Paulo Moreira, Arraial do Cabo, Rio de Janeiro, Brazil

The marine macroalgae correspond as habitat very suitable for settlement of sessile animals, but the marine algae invest in production of defense fenolics substance that can to influence the distribution of the sessile animals upon the plants. In this study, we tested the hypothesis that there is difference in colonization of Bryozoans between the natural (Sargassum furcatum: Phaeophyta) and artificial plants. The study site were, Cabo Frio Island, Arraial do Cabo, Rio de Janeiro, Brazil. Aquarium plants (artificial plants) were implanted between natural plants of S. furcatum. The period of sampling was from November 1999 to April 2000. Were identification 18 species of bryozoans: Aetea sica, Amathia distans, Beania intermedia, Bicellariella ciliata, Bugula neritina, B. turrita, B. uniserialis, Crisevia pseudosolena, Crisia ramosa, Disporella pila, Electra bellula, Scrupocellaria cornigera, Siniopelta costazii, Savignyella lafontii, Schizoporella errata, Victorella and Watersipora cucullata. The difference existent between natural and artificial plants was: A) composition of species, where occurred exclusive species: S. furcatum: A. distans, B. ciliata, E. bellula, S. lafontii and N. gigantea. Artificial plants: B. turrita, S. cornigera and S. errata. B) Number of species: leaf of S. furcatum: 6 species; leaf of artificial plant: 8 species; stem of S. furcatum: 14 species; stem artificial plant: 12 species. The difference it may be since structure of plant and not caused by antifouling substance (fenolics), so when compare the S. furcatum with artificial plant the difference continue the same condition, the number of species in stem larger than in the leaf. But is need to make other experiments for confirmation, then other feature can be influencing this difference.

Bryozoan species in depositional sequences, Ordovician (Trentonian and Cincinnatian), Cincinnati Arch region, U.S.A.

June R.P. Ross
Department of Biology, Western Washington University, Bellingham, WA 98225, USA

Charles A. Ross
Department of Geology, Western Washington University, Bellingham, WA 98225, USA

Various biostratigraphic and lithostratigraphic models have been used to interpret the complex facies and age relationships of the Lexington Limestone (Trentonian) and Cincinnatian strata of the Cincinnati Arch region. Recently, several new efforts have tried to identify unique depositional events, such as volcanic ash layers, tectonically disrupted sedimentation, and regional unconformities. We consider regional unconformities, particularly those thought to separate the succession into depositional sequences, and compare them with stratigraphic ranges of bryozoan species.

The Lexington Limestone rests unconformably on the Tyrone Formation which was irregularly eroded to a depth of as much as 8 m. This eroded surface is a widely recognized sequence boundary event throughout the Mid-western states and northward into New York State. The middle part of the Lexington shows off-lapping relations away from the axis of the Jessamine Dome and marks a regional lowering of sea-level. These beds are overlain by a transgressive sytems tract. On the Jessamine Dome, they form a shallow carbonate platform of calcarenites, calcareous packstones, and grainstones (Tanglewood Bank). Off the flanks of this carbonate bank different facies expand and contract and change abruptly into a siltstone-calcisiltite-wackestone facies of the Clays Ferry Formation, apparently in response to minor changes in sea-level. Bryozoans from the lower Lexington include more than fifteen species, of which at least seven range upward into the overlying upper Lexington. Many bryozoans, such as Parahallopora nodulosa, Heterotrypa foliacea, Peronopora vera and P. milleri, first appear in the lower part of the Clays Ferry or in equivalent carbonates of the Tanglewood facies. Eridotrypa mutabilis is common and Constellaria teres is rare in this interval; both first appear in the upper beds of the underlying Grier Member.

Tongues of the upper Lexington extend northward and appear in the lowest part of the Kope Formation (i.e., Point Pleasant Member). Most of the Kope marks a sea-level deepening event and has a low bryozoan diversely of presumably deeper water species. A higher zone, above a possible mid-Kope shallowing event, has Batostoma jamesi. General shallowing near the top of the Kope brings a return to more carbonate-rich shales and siltstones (McMicken Member) and the introduction of Dekayia aspera and about six other species which form the highest Edenian bryozoan zone.

Continued gradual shallowing through the Maysvillian Fairview Formation is accompanied by the introduction of many additional bryozoan species of Dekayia, Heterotrypa, Homotrypa, Batostoma, Amplexopora, Atactoporella, most of which range upward into the Arnheim Formation where they become extinct. Only a few survived into the Waynesville Formation or higher.

Waynesville, Liberty, and Whitewater bryozoans are much reduced in species diversity with only a dozen common species and less than a dozen relatively rare species. Whitewater bryozoans include only four common species and eight rarer species.

A new unusual cheilostome bryozoan from Mediterranean Pliocene deep-sea sediments.

Antonietta Rosso
Dipartimento di Scienze Geologiche, Sezione di Oceanologia e Paleoecologia, Università di Catania, Corso Italia, 55, 95129 Catania, Italy

During the study of bryozoan assemblages from Pliocene deep-sea sediments cropping out in NE Sicily, some new species were found.

One of them appear to be particularly interesting for the peculiarity of some characters and, above all, for their combination. It is particularly unusual with respect to other known living and Pliocene and Pleistocene deep-sea species from the Mediterranean area and also from the near Atlantic unlike several other species from the same assemblages which are presently living in the NE Atlantic or which have there their counterparts.

The studied new species shows superficial similarities only with Thychinella schreibersi (Reuss), an Eocene species from North Italy and the Carpathian area. Nevertheless, some differences (i.e. orifice and frontal wall morphology, presence of kenozooids and growth habit) suggest to distinguish the two species which cannot be assigned never to the same genus.

To suitably allocate the new species, a new genus is therefore created and its systematic position within the Cheilostome Lepraliomorpha is discussed together with relationships with other similar taxa.

Finally, hypotheses about the life habit of the new species are put forward taking into account its morphological features and its potential use as a palaeloecological tool is discussed.

Life history characters and ecology of some incrusting ctenostomates.

John S. Ryland
School of Biological Sciences, University of Wales Swansea, Swansea SA2 8PP, UK

Four encrusting ctenostomates occur on intertidal Fucus serratus in South Wales: Alcyonidium gelatinosum, A. hirsutum, A. reticulum and Flustrellidra hispida. At the time of a previous study (1996-97), following the Sea Empress oil spillage in February 1996 that contaminated Milford Haven, A. reticulum had not been distinguished from the very similar A. gelatinosum. Their breeding seasons were of course then undifferentiated and the full extent to which the pollution affected recruitment therefore remained unclear. To clarify these uncertainties a further study year's study was undertaken (December 1997 to February 1999). Settlement seasons of the three Alcyonidium species, together with that of the cohabiting F. hispida, have been established from 80 samples, each of twenty 10 cm long F. serratus frond extremities. The results will be presented. Size differences of ancestrulae, though present (reflecting pronounced differences in embryo size), are insufficient to distinguish the species, but the contemporaneously settling A. hirsutum and A. reticulum differ in early astogeny; A. gelatinosum shows the same initial budding pattern as the very similar A. reticulum but, in South Wales, releases its larvae at a different time. The temporal separation of the period of recruitment of the two similar species, A. gelatinosum and A. reticulum, results in their occupying different zones of the algal thallus. F. hispida zooids are so much larger than those of Alcyonidium that it may not be a ‘closely related species’ in the non niche-sharing sense of Gause’s hypothesis; but its settlement season is temporally well separated from that of A. hirsutum, with which - in more exposed situations - it often partitions F. serratus thalli in the same way as seen in A. gelatinosum and A. reticulum.

Late Eocene Bryozoan assemblages of the St Vincent Basin, South Australia - preliminary results.

Rolf Schmidt and Yvonne Bone
Department of Geology & Geophysics, Adelaide University, Adelaide, S.A. 5001, Australia

The first extensive and stratigraphically detailed taxonomic study of fossil bryozoans within the Late Eocene sediments of the St Vincent Basin has revealed a range of faunas from very high abundance and diversity to almost monotypic assemblages. The Tortachilla Limestone is often composed of mostly bryozoan fragments and in places can contain well over 150 species of cheilostomes and over 50 species of cyclostomes. This is probably more than all other macrofauna present combined. The Phidoloporidae represent the most diverse (and ubiquitous) group with over 15 species, at a time which is very close to their estimated origination. Cellariidae are also well represented with over 12 species. Lunulitiform growthform is popular and is displayed by the families Otionellidae, Lepraliellidae, Calloporidae. Biogeographical comparisons have been hampered by the absence of other stratigraphically constrained detailed species lists for most of the Australian Tertiary limestones. Comparison with the published (mainly Neogene) fossil bryofaunas of Victoria exhibits distinct differences in the bryofaunas that existed in each region. Interesting is the apparent absence in the St Vincent Basin of groups which are generally common in Victorian Tertiary deposits (as well as the modern shelf), such as the Microporellidae and any species of Selenaria. Although the Cellariidae are a very common component of both regions, the actual species are highly dissimilar. Such dissimilarities may be the result of the restricted nature of the St Vincent Basin Basin during much of the Tertiary caused by a basement high centered on what is now Kangaroo Island. This situation created a range of environments not encountered in the other basins. It could also have formed a type of geographic faunal barrier. The large number of new species and several new genera described further adds to the high global diversity of the Late Eocene.

Bryozoan Morphoprocesses

Joachim Scholz
Forschungsinstitut und Naturmuseum Senckenberg, Sektion Marine Evertebraten III, Senckenberganlage 25, D-60325 Frankfurt, Germany

George S. Levit
AG Geomicrobiology/Geophysiology, Institute for Chemistry and Biology of the Marine Environment (ICBM), Carl von Ossietzky University of Oldenburg, Carl-von-Ossietzky-Str. 9-11, POB 2503, D-26111 Oldenburg, Germany

In the following notions, bryozoan regular growth and change is described consistent with the language and ideas of the Russian zoologist V. N. Beklemishev (1890-1962). He described the totality of living matter on earth as global morphoprocess. Morphoprocess is a dynamic form of organization of living matter, thereby replacing from the certain viewpoint the concept of organism.

Accordingly, bryozoans are introduced as complex entities composed of many biosystems such as associated microbial cells living on and within bryozoan tissues. Bryozoans being to a certain extend a genetically defined species is thus of rather relative nature when it comes to environmental interaction: some bryozoan species are actually a microbial mat with underlying bryozoan zooids (bryozoan microreefs); colonies of other bryozoans look clean, but support extensive fungal mycelia growth inside their coelomic cavities.

Does the degree of association of bryozoans with microorganisms translate into morphological signatures?

Generally spoken, bryozoan zooids and colonies are polar structures. The structural polarity is e.g. evident by the arrangement of pore chambers which shall give rise to a daughter zooid. In planar growth, the sum of sequences of mother-daughter zooids results in a geometrical void-filling arrangement. Environmental factors such as competition for space may cause a change in the arrangement of autozooids. As an induced (reactive) polarization of colonial (zoarial) growth, they superimpose the structural polarity of zooids and may result in "equipotential", aclonal areas of the zoarium.

The presence of highly reactive equipotential areas characterises the zoarial margins and/or frontal surfaces of many planar-encrusting bryozoans. There are various species-specific degrees of structural polarity or potential of induced polarity. It has thus been possible to group encrusting multilinear zoarial types into four basic classes. Increasing degrees in the formation of an equi-potential marginal area are achieved in the following order: zooidal laminae, multizooidal laminae, celleporiform laminae and sheet laminae.

The selection of spatial (latitudinal and bathymetric) occurence of growth types is mainly linked to the competitive pressure of microbial mats, or mutalistic interaction with epizoic mats (the talk co-authored by Juergen Kaselowsky, Shunsuke F. Mawatari, and Gero Hillmer introduces some quantitative data on that line). The higher the degree of mutuality and, hence, the level of functional harmony of the bryozoan biosystem, the more morphogenetically secluded it becomes (e.g. bryozoan microreefs).

On the other hand, competitive interactions of bryozoans with biomats results in a high degree of variation of zoarial forms (e.g. bryostromatolites).

Behavioral peculiarities in marine bryozoans depending on tentacle structure.

Natalia N. Shunatova
Department of Invertebrate Zoology, Faculty of Biology & Soil Science, St.-Petersburg State University, Universitetskaya emb. 7/9, St.-Petersburg, 199034, Russia

Earlier obtained data on polypide behavior of 39 gymnolaemate species suggested that species from different taxanomic groups have some pecularities in the construction and fuctioning of thier filtration apparatus. Since polypide behavior is very scanty in some species but very diverse in others, species studied were accordingly distinguished in two groups. Stenolaemates (first group) demonstrate only ciliature beating and tentacle flicks. Eurystomates from the first group in addition are able to perform nods and rotation movements of introvert. But never species from the first group use diverse tentacle movements as species from the second group do.

Tentacle construction was studied in 23 species of marine bryozoans. These results conclude that all gymnolaemates have similar general tentacle construction that nevertheless varying in details (such as lateral cilia length, number of frontal cilia, degree of longitudinal muscle development) in different species. Taking into consideration these differences 2 groups of species were marked out. Species from the first group are characterized by "long" lateral cilia, few and thinner longitudinal muscle bundles and few (or absence of) frontal cilia. Second group includes species with "short" lateral cilia, more numerous and thicker longitudional muscle bundles and numerous frontal cilia. The correlation between tentacle structure pecularities and feeding behavior was found out: species from the second group are characterized by more diverse behavioral reactions than those from the first one.

So, we can conclude that in species from the first group not tentacle movement but ciliature beating is the most important during feeding process. It is possible that another lateral cilia length ratio to tentacle width enables to form more effective filter. On the contrary, in species from the second group active tentacle movements might play a significant role in feeding.

Sensory structures in gymnolaemate bryozoans.

Natalia N. Shunatova
Department of Inveretebrate Zoology, Faculty of Biology & Soil Science, St. Petersburg State University, Universitetskaya emb. 7/9, St.-Petersburg, 199034, Russia

Claus Nielsen
Zoological Museum, Universitetsparken 15, DK-2100, Copenhagen Ø, Denmark

SEM studies of 21 species of marine bryozoans demonstrated that the abfrontal side of the tentacles bears a row of mono- or multiciliate cells, which are presumably sensory. Stenolaemates have only monociliate abfrontal cells and also the cells at the tentacle tips and the laterofrontal cells are monociliate. In the 17 gymnolaemate species studied, each tentacle tip carries at least 3 multiciliated cells, each with a tuft of varying length and consisting of 5-7 stiff cilia. On the abfrontal tentacle surface, mono- and multiciliate cells alternate, but all species studied have multiciliate cells at the base and the tip of the tentacle. Observations on live animals demonstrated that single cilia perform occasional flicks, whereas the tufts of 7-15 cilia on the multiciliate cells are immotile. Length and number of abfrontal cilia vary between species.

Two types of multiciliate, probably sensory organs were found on the introvert of some gymnolaemates. One has an apical knob surrounded by a ring of cilia; the other has an apical tuft of cilia. The ultrastructure of multiciliate sensory cells of tentacles and introvert was studied in Rhamphostomella ovata. Both their structure and observations and experiments with live bryozoans suggest that these cells are mechanoreceptors of a primitive type. The few species lacking ciliary structures on the introvert have very long proximal ciliary tufts on abfrontal tentacle surface.

Structure-functional organization of freshwater invertebrate communities with domination of Plumatella emarginata (Bryozoa).

Olga O. Sinitsina
Institute of Hydrobiology, Academy of Sciences of Ukraine, Kiev, 04210. Ukraine

The research of periphyton and benthos communities with prevalence on a biomass Bryozoa was conducted on 7 cooling ponds of thermal and nuclear stations of Ukraine and Poland in summer period 1980- 2000. From three discovered species of Bryozoa Plumatella fungosa and Cristatella mucedo live mainly in zones of pools with natural temperatures, and in pools of such type meet incidentally. Thermophilic species of Bryozoa - Plumatella emarginata (Pall.) is a typical component of periphyton and benthos communities (on depth from a shore line up to 6 metre) in zones directly contacting with fault of heated waters of power objects (t = 28-35 degree Celsius). The straight line a correlation of a biomass P. emarginata with temperature and tendency of increase of a biomass with depth is marked. The communities with prevalence P.emarginata are characterized by high riches of species (67 tacson), most diversly are represent Oligohaeta (19 species), Chironomidae (10 species), Gastropoda (8 species ). The biomass P. emarginata in different biotopes of investigated ponds changed in broad limits (from 0,82 up to 2636,86 gram per square metre). With increase of a biomass of a species - dominant is marked increase of variety and complication of communities structure : reches of species , on the average, on the order; diversity index of Shannon on number - almost in 1,5 times; increase of total number of organisms at 2-3 order. One of directions of effect of abundance of a species - dominant on structurally- functional organization of communities - increase of spatial complexity of localities of organisms coexistent with P. emarginata. The colonies Bryozoa of this species already at a biomass of the order 500 g/m2 represent multilayer heterogeneos structure. Other aspect - enrichment of a food supply of the relevant trophic component of communities - detritophagous animals - collectors - at the expense of sedimentation of suspended matter by P. emarginata. Abundance of the detritophagous animals at a low level of development the dominant makes 273 ind/g P. emarginata, and at a biomass P. emarginata of the order 1 kg/m2 increases almost in 3,5 times. At increase of a biomass the dominant structurally- functional changes of its separate components is accompanied by reallocation of energy flow through community: the trophic circuit the filttator - sedimentator - detritophagous animals - collectors becomes complicated at the expense of occurrence of animal other trophic groups, particularly, is supplemented by predators. The straight line a correlation of a biomass of this species of dominant with quantities energy of destruction by community, coming on 1 bit of the information about variety of its components, testifies about increase of its power inputs on maintenance of more composite system. The increase of variety of components of Bryozoa’s community in range from 0,214 - 2,000 up to 3,039 bits / ind augments power inputs of community more, than in 4 times. NOT PRESENTED

Paludicella articulata in Dunedin: native or alien?

Abigail M. Smith
Department of Marine Science, University of Otago, P. O. Box 56, Dunedin, New Zealand

Judy Broom
Department of Biochemistry, University of Otago, P. O. Box 56, Dunedin, New Zealand

Paludicella articulata has been found in freshwater reservoirs of Dunedin (South Island, New Zealand) since1902. Since 1996 it has grown profusely in Dunedin's Southern Reservoir, clogging microstrainers and causing considerable damage; its presence costs the Dunedin City Council many thousands of dollars per year. While Paludicella articulata is a widely dispersed bryozoan, reported from Quebec Canada to northern Norway and Poland, the only record of its presence in the southern hemisphere is at Southern Reservoir, Dunedin. This distribution suggests that it may have been introduced to New Zealand early in the period of European settlement. Perhaps pipes or equipment from Europe infested with Paludicella hibernacula (resting cysts) were used in construction of Dunedin's water supply system. Alternatively, it may be that Paludicella articulata is naturally found throughout the southern hemisphere, but has not been identified and documented. Here we appeal to members of the IBA for two pieces of this puzzle: we are asking for specimens of northern Paludicella articulata for DNA sequencing and comparison with southern specimens, and we would like to hear if any IBA members have ever found Paludicella articulata elsewhere in the southern hemisphere.

Adeonellopsis sp. in Doubtful Sound - a surprisingly long-lived bryozoan.

Abigail M. Smith and Brian Stewart
Department of Marine Science, University of Otago, P.O. Box 56, Dunedin, New Zealand

Marcus M. Key, Jr.
Department of Geology, Dickinson College, P.O. Box 1773, Carlisle, PA 17013-2896, USA

Catherine M. Jamet
Department of Geology, Indiana University-Purdue University, 723 W. Michigan St., Indianapolis, IN 46202-5132, USA

While most extant bryozoans are small and encrusting, in New Zealand many large erect species provide important ecological habitats and produce enormous quantities of carbonate sediment on the open shelf. We investigated growth of the prominent rock-wall bryozoan Adeonellopsis sp, which grows in diveable depths on rock walls in Doubtful Sound, southwestern New Zealand. Morphometric study, radiocarbon dating, stable isotope profiling, and in situ marking with calcein were all used to determine growth rate and age. Radiocarbon dating gave an upper limit of 50 years for the age of a very large Adeonellopsis colony. Marking with calcein showed that new branches grow at 6.9 mm/y. When combined with morphometric parameters, this growth rate would result in a large colony being about 20 years old. Isotopic profiling results have not yet been analysed but will be presented. We show that taking a multi-pronged approach to age analysis leads to a robust understanding of growth and development of large erect bryozoans, and that Adeonellopsis sp. in Doubtful Sound is one of the oldest bryozoans yet studied, providing a stable microenvironment over time.

Phylogenetic relationships of Wenlock Bryozoa.

Joanna F. Snell
School of Earth Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK

The Wenlock Series (423-428 Ma) of Wales and the Welsh Borderland, UK, records a time when this area was covered by a relatively warm, shallow shelf sea, with the edge of the continental shelf lying to the west. Today, fossils from the Much Wenlock Limestone Formation of this area comprise the faunal remnants of small tropical reefs, and a variety of associated reef and inter-reef dwelling organisms, which reflect a shallow-water carbonate shelf ecosystem. Over 600 species have been recorded from this formation, representing almost 30 major taxonomic groups, although the limestones are typically dominated by the skeletal remains of crinoids, corals, brachiopods, trilobites, algae and bryozoans. By comparison with post-Palaeozoic faunas though, the Wenlock Bryozoa have so far remained poorly studied and are little understood. Indeed, previous taxonomic concepts have been based on insufficiently diagnostic criteria and species descriptions are often lacking.

One of the main causes of confusion among the Wenlock Bryozoa is their homeomorphic nature, particularly at specific level. Furthermore, previous weak and inconsistent techniques used to study the bryozoans have worsened the situation. The first workers tended to rely solely on exterior characters, and although these can be used to distinguish species, a much more rigorous means of analysing these features is needed, rather than just simply describing them. Bryozoans also have an extensive range of interior characters that need to be exploited, when possible, in order to help resolve their systematic biology. The large number of exterior and interior characters that the Bryozoa possess make them ideal for phenetic and cladistic means of classification. Both of these methods were employed in this study in order to resolve species concepts and interrelationships, as well as providing detailed descriptions of the Wenlock Bryozoa from Wales and the Welsh Borderland.

Phenetic methods utilise a variety of numerical tests that can be used to analyse quantitative data sets. The multivariate test of cluster analysis was used in this study though, since it has previously been used to classify bryozoans and the resulting phenograms are clear. Cluster analysis classifies objects (specimens) into groups (species) in a space defined by their morphological characters, by using a previously selected linkage and distance method. A large number of exterior and interior morphological characters are measured from each specimen and this data is entered into a statistical package, Minitab, which carries out the analysis. The results have been very encouraging, identifying species at a similarity level of greater than 95%, with only a few discrepancies, as well as providing some information on the hierarchical classifications and relationships within the Wenlock Bryozoa, which can be further tested using cladistics. Traditional cladists have tended to only use qualitative characters, but this study also incorporated morphometric data, by converting the numerical ranges into discrete character states. The final cladograms show few unresolved relationships, and furthermore, some of the subclades in the cladograms do have counterparts in the phenograms.

Using both techniques in conjunction (phenetics to identify natural species groups and cladistics to analyse phylogenetic relationships) enables a rigorous analysis of the systematic palaeontology of Wenlock bryozoans. NOT PRESENTED

Dendroid Bryozoa of the Warsaw Formation (Valmeyeran) of the Mississippi River Outcrop Belt, Illinois, USA.

Edward M. Snyder
Institute for Environmental Studies, Shepherd College, Shepherdstown, WV 25443, USA

Daniel B. Blake
Department of Geology, University of Illinois, Urbana-Champaign, Il 61801 USA

Steven J. Hageman
Department of Geology, Appalachian State University, Boone NC, 28608 USA

Dendroid Bryozoa, represented by members of the Orders Cryptostomata and Trepostomata, constitute a diverse and abundant component of the fauna present in the Middle Mississippian Warsaw Formation of the Mississippi River outcrop belt. Sixteen species of the Order Cryptostomata are present, representing the following families; Rhabdomesidae, Rhomboporidae, Bactroporidae, Nikiforovellidae and Hyphasmoporidae. Three species of the Order Trepostomata occur in the Warsaw, all belonging to the Family Stenoporidae. Nine previously described species are recognized; Rhabdomeson rhombicus Ulrich, 1890, Mediapora asperula (Ulrich, 1890), Nicklesopora varians (Ulrich, 1890), Saffordotaxis incrassata (Ulrich, 1890), Bactropora simplex Ulrich, 1890, Streblotrypella major (Ulrich, 1890), Streblotrypa nicklesi Ulrich, 1890, Streblotrypa radialis Ulrich,1890, Leioclema gracillimum Ulrich, 1890. One new genus and species, and nine new species are recognized. New species belong to the following genera; Rhabdomeson, Ascopora, Mediapora, Trematella, Nikiforovella, Hyphasmopora, Streblotrypa, Dyscritella, and Leioclema.

Exterior and interior analysis of bryozoan zoaria are employed in classification of Warsaw dendroid Bryozoa. The outline employed in this study provides a structured taxonomic approach allowing descriptive and quantitative comparison of zooecial and zoarial features. Three-dimensional chamber form, chamber dimensions, stylet type and development, metapore type and development, and septal development are emphasized in taxonomic analysis.

Descriptive and quantitative analyses were employed in taxonomic assignment of species. Zooecial characteristics including aperture size, shape and dimensions; zooecial shape and dimensions; hemiseptal development and placement; stylet size and shape; and metapore size, shape and development are highly consistent characteristics within species. Zoarial characteristics are more variable, as evidenced by consistency of endozonal thickness, exozonal thickness, branch width, and branch placement.

Changing concepts in species diversity in the northeastern Pacific: e.g., Will the real Parasmittina trispinosa please stand up ?

Dorothy F. Soule and John D. Soule
Allan Hancock Institute of Marine Studies, University of Southern California, Los Angeles, CA 90089-0371, USA

Penny A. Morris
Natural Sciences Department, University of Houston, Downtown, One Main St. Houston, TX 77002, USA and NASA, Johnson Space Center, Houston, TX 77002,USA

When a relatively small area of the northeastern Pacific, the Santa Barbara Basin and Western Santa Barbara Channel, was sampled by dredge, a total of 118 species were identified, from which six new genera and 44 new species were described (D.F. Soule, J.D. Soule and H.W. Chaney, 1995). New species thus constituted 37 percent of the total. Virtually all of these new species had been included in the so-called wide range of variation of previously described species, identified by Osburn (1950, 1952, 1953). The type localities ranged from Patagonia to the Arctic Circle, from Britain to Africa, and from Australia, These "highly variable species" were then considered to be cosmopolitan or close to it.

The British species Parasmittina trispinosa (Johnston, 1825) is an example of a species previously considered to be cosmopolitan, recorded by Hincks, Robertson, the O’Donoghues, Hastings and Osburn (1952) from British Columbia to the Galapagos Islands. Recent research indicates that it probably does not occur in the eastern Pacific at all. Many more such "species" require SEM examination of specimens to confirm that there is at least a 37 percent level of differentiation, and this type of analysis will undoubtedly increase the number of new species.

The advent of SEM has changed our ability to distinguish consistent phenotypic differences, and eventually techniques such as DNA will separate species even more accurately. The change in optics emphasizes the need for change in the concept of cosmopolitanism, decreasing its incidence considerably. More important, this would change our perspective on how many living species might exist. The concepts that most species remained stable over long periods of time and that they exist over wide ranges of habitat or climatic variation must also be reevaluated. When habitats are examined for environmental impacts, as is required by U.S.A. Federal and State law, the impression that species are stable over such wide ranges of habitat and climate exacerbates the assumption that these species are of negligible importance in the analysis of localized project impacts. Revealing the hidden diversity must be made a greater priority than is now accorded to bryozoan species in order to help protect areas from environmental degradation.

Bryozoans from inside closed bivalve shells in the Pliocene of Rhodes, Greece.

Nils Spjeldnaes
Universitet i Oslo, Institutt for Geologi, BOKS 1047, Blindern, 0316 Oslo, Norway

Pierre Moissette
Université de Lyon I, UFR Sciences de la Terre, 27 Bd du 11 novembre, 69622 Villeurbanne Cedex, France

Bryozoans are common incrusters of mollusc shells (living and dead) and other hard substrates. They are often found in cryptic environments, which may give advantages to the bryozoans, both as a shelter against physical damage, competitors and predators, and access to nutrient-rich shallow water for species normally living in deeper water with less light. Cryptic bryozoans often seem to be specialised forms, which may correspond to physiological adaptations to cope with these environments, especially temporary oxygen deficiency. Such specialisations are seen also in fossil material, even if it is normally not possible to estimate the exact physiological parameters.

In the very rich Pliocene-Pleistocene marine faunas of Rhodes, there are some examples of bryozoans incrusting the interior of bivalves preserved with both valves closed. This may indicate very restricted environments, and the material has been analysed to explain the palaeoecology of the bryozoans.

The bivalves involved are mostly Pecten jacobaeus, Chlamys (Aequipecten) orbicularis and Glossus humanus, and most of the specimens are found in live position. The pectinids are normally living horizontally in the sediment, and the tight closing of the valves may be due to later sediment weight. Glossus is peculiar in that the ligament does not normally open the valves after the death of the animal


An analysis of the bryozoans found inside the shells (about twenty species, almost exclusively cheilostomes) indicates that they also occur in other cryptic environments, especially in shallow waters. One of the main problem is how the bryozoan larvae entered these cryptic places if they had to penetrate through the sediment. The colonies encrusting the inside of the bivalve shells are generally of small size and iron-stained which may also indicate anoxic conditions. The occurrence in the visceral coelom of many cheilostome bryozoans of chemosynthetic symbiontic bacteria, perhaps oxygen-producing, may allow them to sustain the anoxic conditions prevailing in this peculiar environment.

Brooding in the Cretaceous bryozoan Stichomicropora and the origin of ovicells in cheilostomes.

Paul D. Taylor
Department of Palaeontology, The Natural History Museum, Cromwell Road, London, SW7 5BD, UK

Frank K. McKinney
Department of Geology, Appalachian State University, Boone, North Carolina 28608, USA

The Cenomanian-Maastrichtian microporid cheilostome Stichomicropora Voigt, 1949 has unique ovicells which are normally preserved only as a transverse crescent of tiny pores on the frontal wall of the zooid distal of the brooding zooid. Varying in number from 4-10 according to species, the pores are located along the mural rim at the boundary between an enlarged proximal gymnocyst and the extensive cryptocyst. Intact ovicells in the Maastrichtian species S. baccata (Canu and Bassler, 1926) from Tennessee and Alabama show that these pores are the bases of flattened, hollow spines which are arched proximally and fused along their edges to produce a costate ovicell roof. This information has a bearing on the evolutionary origin of ovicells in Stichomicropora specifically and more generally in cheilostomes as a group. Maternal zooids possess the normal complement of oral spine bases, suggesting that Stichomicropora ovicells are not derived by modification of maternal oral spines. The presence in the ancestrula of additional, proximal mural spine bases demonstrates the potential for zooids to develop mural spines in locations well proximal of the orifice. Positional homologies therefore lead to the conclusion that the Stichomicropora ovicell is derived entirely from the distal zooid, with the roof constructed by the 4-10 mural spines and the floor by the proximal gymnocyst. This new evidence from Stichomicropora is consistent with the long-standing hypothesis that ovicells in cheilostomes are derived from spines. The early appearance (Lower Cenomanian) of Stichomicropora in the fossil record, not long after the oldest records (Upper Albian) of cheilostome ovicells, lends further support to the hypothesis. However, Stichomicropora is unusual in that each ovicell is formed from a large number of spines whereas in other cheilostomes only one or two spines normally contribute to ovicell formation. It is unclear whether this feature is an apomorphy of Stichomicropora or represents the primitive condition for cheilostome ovicells.

The effects of increased external Ca++ and K+ concentrations on the waveform dynamics of bryozoan spermatozeugmata.

Michael H. Temkin
Biology Department, St. Lawrence University, Canton, NY 13617, USA

The gymnolaemate bryozoan Membranipora membranacea spawns spermatozeugmata, aggregates of 32 or 64 sperm. In my previous studies, spermatozeugmata have been observed to generate at least three distinct waveforms: type I, a low amplitude, head to tail wave that represents the predominant waveform; type II, a high amplitude head to tail wave; and type III, a tail to head wave. Spermatozeugmata within the paternal coelom produce type III waveforms with greater frequency and for longer periods of time than spermatozeugmata in the water column. Spermatozeugmata use the type III waves to propel themselves out of the paternal tentacles during spawning. Type III waves have also been observed when spermatozeugmata contact intertentacular organs, a tubular structure spermatozeugmata pass through to enter maternal zooids. Here, to investigate how M. membranacea sperm modulate their waveforms, spermatozeugmata were exposed to elevated concentrations of external Ca++ (10, 20, 30, and 40 mM) and K+ (10 and 20 mM). Increasing the external Ca++ levels by 20 and 30 mM caused spermatozeugmata outside of the paternal coelom to increase the duration of type III wave events, but did not affect the frequency of type III wave events. Increasing external Ca++ by 40 mM or increasing external K+ by 10 or 20 mM produced a fourth wave pattern. Type IV waves are propagated in the same direction as type III waves, moving along the axoneme from tail to head. However during the generation of type IV waves, the anterior ends of the spermatozeugmata go through an effective stroke/recovery stroke motion comparable to the movement of cilia. The movement of sperm aggregates during type IV waves generates enough motive force to propel spermatozeugmata through the water column and may be the waveform used to pull spermatozeugmata into intertentacular organs to enter maternal zooids.

Bryozoans, parasites, and fish farms.

Sylvie Tops and Beth Okamura
School of Animal and Microbial Sciences, University of Reading, Reading, RG6 6AJ, UK

Tetracapsula bryosalmonae is the recently described myxozoan that develops as an endoparasite of freshwater bryozoans and causes Proliferative Kidney Disease (PKD) in both farmed and wild salmonids. The discovery that bryozoans are the source of the causative agent of PKD opens up many new avenues of investigation with regard to understanding the nature and potential control of the disease in salmonid fisheries. Of primary interest is the ecology of T. bryosalmonae in bryozoan populations. Early information on the incidence and prevalence of T. bryosalmonae in bryozoans will be reviewed, and preliminary results of investigations in southern England will be presented.

New bryozoan faunas from the Miocene of Burgenland (Austria).

Norbert Vávra
Institute of Paleontology, University of Vienna, A-1090 Vienna, Austria

In the Miocene of Burgenland there exists a considerable number of outstanding outcrops of bryozoan-bearing sediments; among them various sections in the so-called "Terebratula-sands" at Eisenstadt are the most important ones: for approximately 50 species Eisenstadt ( a "classical" fauna studied already by Reuss, Manzoni, Canu and Bassler and many others) being their type locality. In addition there exists also a number of various other outcrops having yielded excellent bryozoan faunas too. From two of these localities new resp. unpublished material is to be presented in this paper: Forchtenstein (20 km SW Eisenstadt) and Stotzing (7 km NNE Eisenstadt). Unfortunately the outcrops at Forchtenstein are not accessible anymore; Bobies however had collected in the late 50s an extremely well-preserved and rich fauna of remarkable high diversity which has not been published until now. This material being kept at the Museum of Natural History (Vienna) is the basis for these studies. The other fauna (Stotzing) has been recently discovered by a young colleague (Dr. H. Temmel, Vienna) in a sandy facies of the Badenian (Middle Miocene). The most outstanding feature of this material is the occurrence of unusual large and well-preserved zoaria for many genera (e.g.: Hornera, Metrarabdotos, Polyascosoecia, Smittina, Steginoporella) including also a considerable number of rather rare taxa (e.g.: Hincksina loxopora, Kionidella, Tremogasterina areolata, Tremopora radicifera). For the first time a complete zoarium of Bobiesipora fasciculata could be detected in this material too. These two faunas have not only contributed further data concerning occurrence and distributional patterns of various taxa in space and time but have also yielded many additional informations in respect to taxonomy, paleoecology and paleobiogeographical aspects of the Central Paratethys.

The phylogeny of Northern European Bowerbankia species.

Andrea Wäschenbach, Peter J. Hayward and David O.F. Skibinski
University of Wales, Swansea, Biological Sciences, Swansea, SA2 8PP, UK

Mitochondrial DNA sequences have been obtained for five species of the Ctenostome bryozoan Bowerbankia in order to devise a phylogenetic tree. Extensive sampling throughout the British Isles has provided material for the taxonomic analysis of this genus, where sequence variations provide divergence estimates between species. Particular attention has been given to the problem between B. gracilis Leidy (1855) and B. caudata Hincks (1880), which are currently considered to be one species, but exhibit distinguishing morphological differences.

Functional morphology of the foliose coalescing growth form in Heterotrypa frondosa (d'Orbigny) (Bryozoa: Trepostomata) from the Cincinnatian (Ordovician) of Ohio.

David A. Waugh Department of Geology, Kent State University, Kent, OH 44242, USA

J. Mark Erickson Department of Geology, St. Lawrence University, Canton, NY, 13617, USA

It has been rare for paleontologists to reconstruct bryozoan zoaria from the fragmented remains that generally represent these structures in the Paleozoic rock record. Without reconstructed specimens, however, there can be little understanding of the functions of the colony, its range of phenotypic variation, or the range of ecological conditions for which the species was adapted. A limestone-to-shale interval near the contact between the Maysvillian Fairview and Bellevue Formations has yielded large portions of the skeleton of Heterotrypa frondosa (d'Orbigny) in crushed, fragmented form that was reconstructed after careful collecting of more than 60 pieces. Growth form and function of one such colony are analyzed herein.

From an encrusting base (not recovered), upward growth of three blades led to a system of archways, or windows, and then to chambers formed from coalescing blades thus creating a morphology that allowed water circulation upward and outward through the chambers. This was a passive flow situation in which external currents drove water through the colony whereas ciliary beat of lophophores created food capturing opportunities. Chambers generally developed as irregular, tube-shaped structures with vertically-elongate lower openings (windows) leading to expanded medial regions with narrowed, subcircular, upper openings. Chambers were 4.8 to 9.0 cm in length and 0.5 to 3.0 cm in diameter in our specimen. A plaster cast of the specimen permitted preparation of longitudinal and transverse sections of the colony that reveal the relationships of chambers. Study in a re-circulating flume using a thermistor-based flow meter and dye, allowed analysis of water movements.

Two conditions were recognized in the flume. First, water velocity was slowed in the chambers; secondly, turbulence was created within the chambers. With slowed velocity, food particles may have settled a bit, a stilling-chamber effect, that produced longer residency time for water and suspended food, thus increasing capture opportunities. Turbulence in the chambers is assumed beneficial to these filter feeders, allowing the interior parts of the colony to feed without receiving water depleted in nutrients by other zooids; the turbulence immediately mixed fresh and food-depleted water, perhaps retaining food-rich waters in the water mix longer before flushing, as a non-chambered system would have done. Colony morphology also allowed granular sediments to be funneled downward and outward by gravity. The chambers and coalesced blades created a robust, internally-buttressed zoarium that was able to withstand normal, shallow-water, wave conditions and occasional storm surges. Against massive storms they were less defensible.

Deconstructing bryozoans

Judith E. Winston
Virginia Museum of Natural History, Martinsville, VA 24112, USA

Ruth Ann Dewel and Frank K. McKinney
Appalachian State University, Boone, NC 28608, USA

One of the greatest enigmas of the fossil record is the delayed appearance of bryozoans relative to other skeletonized metazoans. At their appearance bryozoans were fully differentiated into five discrete stenolaemate orders with a diversity of growth habits. Either bryozoans evolved from an older skeletonized group or they had a long cryptic history. In either case they have been hypothesized to have evolved coloniality through asexual budding and miniaturization from a macroscopic lophophorate or "worm-like" ancestor. However, neither miniaturization of the adult individual nor adultation during development can account for the uniqueness of bryozoan embryology and body structure.

The mouth and anus of the sexually produced ancestrula of bryozoan colonies are formed far from the site of gastrulation, which contrasts with their placement in other adult metazoans. Although the mouth in the few larvae having a functional (or non-functional rudimentary) gut may form near the site of blastopore closure, the larval mouth (where present) is unrelated to the mouth of the ancestrular zooid. In fact, the digestive organs of the ancestrula do not originate from the larval gut or gastrulated cells of the embryo but from various parts of the larval epidermis (or perhaps mesoderm in stenolaemates). Nearly all of the larval tissues, including the gut, degenerate in the preancestrula. Post-metamorphic bryozoans lack endodermally derived tissues. In addition, coelomic cavities do not appear to be homologous with those of other metazoans. They are absent in gymnolaemate larvae and the early mesoderm lined cavities of the stenolaemates and phylactolaemates are unrelated to either schizocoely or archenteric outpocketing. Some mesoderm is of epidermal origin. During polypide replacement a cystid consisting or only ectodermal and mesodermal derivatives proliferates a new polypide including a "gut", just as in formation of the ancestrula. The unusual mode of development, apparent absence of endoderm, as well as polypide-cystid duality have important implications. They suggest that prior to the appearance of the phylum in the Ordovician, body plans within the bryozoan stem group had undergone a unique transformation that has placed unusual constraints on the evolutionary history of the lineage.

Freshwater bryozoans: a zoogeographical reassessment.

Timothy S. Wood
Department of Biological Sciences, Wright State University, Dayton, OH 45435, USA

A re-examination of freshwater bryozoans held in various collections worldwide reveals a number of misidentified species. In many cases, the actual species represented are undescribed. Not only does this raise the number of recognized taxa, but it also reduces the presumed geographic ranges of many species once considered cosmopolitan. Examples of such no-longer-widespread species include Plumatella emarginata, P. repens, P. longigemmis, Stolella indica, Fredericella sultana, and Gelatinella toanensis. In fact, the only plumatellid bryozoans now listed from three or more continents are Plumatella casmiana and P. emarginata, and even these are questionable.

The available evidence now suggests that most freshwater bryozoans have a relatively narrow and surprisingly static distribution. Over half of these are known from only a single site. A few other species display apparent disjunct distributions, with at least part of the population occurring in isolated pockets far from a larger body of individuals.

Analysis of these biogeographic patterns raise questions about dispersal mechanisms and the factors that may inhibit the successful establishment of new populations.

Phylactolaemate bryozoans of Great Britain: an update.

Timothy S. Wood
Department of Biological Sciences, Wright State University, Dayton, Ohio 45435 USA

Beth Okamura
School of Animal and Microbial Sciences, University of Reading, Whiteknights, P.O. Box 228, Reading, Berkshire, RG6 6AJ, UK

This study had two primary objectives: to document the distribution of species over a broad area of Britain; and to clarify morphological features by which plumatellid species are distinguished. During four weeks in August and September, 2000, we visited 97 lakes, rivers and ponds in the United Kingdom. Bryozoans were collected by wading, diving, or by leaning over boat docks to scrape colonies from the underside of floating boat fenders (a convenient and effective field technique). Most specimens were preserved in 70% or 100% ethanol. In many instances, live statoblasts were taken and later used to grow new colonies under known laboratory conditions. The following familiar species were encountered: Cristatella mucedo, Fredericella sultana, Hyalinella punctata, Plumatella casmiana, P. emarginata, P. fruticosa, and P. repens. Two undescribed plumatellid species also were confirmed. An additional undescribed plumatellid, known only from Great Yarmouth, was not seen during the survey but is represented in the Museum of Natural History by Specimen No. 1937.12.20.1. Bryozoans known as Plumatella fungosa are shown to comprise two similar groups that maintain their distinctive morphological identities in laboratory culture. Colonies matching the description of Plumatella coralloides appeared among several different plumatellid species, casting serious doubt on the validity of this taxon. Lophopus crystallinus was not encountered during the study, but is believed still to occur in Great Britain, as it does in Europe, as a rare and possibly endangered species. This study brings to 13 the number of phylactolaemate species known from Great Britain. Studies are continuing to fully characterize the new plumatellids and to construct a new taxonomic key for British phylactolaemates.

The reproductive cycle of Plumatella casmiana (Phylactolaemata: Plumatellidae)

Emmy R. Wöss
Department of Limnology, Institute of Ecology and Conservation Biology, University of Vienna, Althanstrasse 14, A-1090 Vienna, Austria

Freshwater bryozoans are unique in their reproduction in that they produce a great variety of asexual propagules; among this group, Plumatella casmiana has developed the highest degree of complexity. It produces three types of statoblasts, two of them with heavily chitinised valves - the sessoblasts and floatoblasts - while the leptoblasts show a very weak degree of chitinisation. Sessoblasts are fixed to the substrate by an attachment apparatus, whereas floatoblasts and leptoblasts develop a swimring that enables them to drift in the water. While sessoblasts and floatoblasts can survive for a longer period, the thin-walled leptoblasts as well as the sexually produced larvae live only for a short time.

A study focussing on the role of the different kinds of propagules in P. casmiana was carried out in the Laxenburg pond in Eastern Austria, where this species was found to be the dominant bryozoan over a period of several years. From May to September, colonies were collected weekly from artificial substrates that had been exposed in this waterbody for one year. The colonies were narcotised, preserved, stained and examined by light microscopy for their gonadal condition and their production of sessoblasts, floatoblasts and leptoblasts.

Results on the investment of P. casmiana in its different modes of propagation show that although testes and ovaria are present from late May to late August, the development of fertilized eggs in the embryosacs was rarely detected. Asexual reproduction and in particular the propagation by leptoblasts seems to play the major role in the reproductive cycle throughout the year.

Astogeny: a comparison between Celleporella carolinensis and C. hyalina.

Peter J. Wright and Roger N. Hughes School of Biological Sciences, University of Wales, Bangor, Gwynedd, LL57 2UW, UK

The talk will describe the astogeny of the cheilostome Celleporella carolinensis, comparing the astogeny of this species with that of C. hyalina. The timing of first reproductive activity in C. carolinensis, which at this stage is believed to occur very early in the life cycle, will be considered in terms of life-history ecology.

Palaeoenvironmental interpretation of the Tramore Limestone Formation (Llandeilo, Ordovician) based on bryozoan colony form and preservation.

Patrick N. Wyse Jackson
Department of Geology, Trinity College, Dublin 2, Ireland

Caroline J. Buttler
Department of Geology, National Museums and Galleries of Wales, Cathays Park, Cardiff CF10 3NP, Wales, UK

Marcus M. Key, Jr.
Department of Geology, Dickinson College, P.O. Box 1773, Carlisle, PA 17013-2896, USA

The Tramore Limestone Formation (Llandeilo, Ordovician), exposed in southeast Ireland, contains well-preserved colonies of the trepostome bryozoan Diplotrypa petropolitana. Two palaeoenvironmental settings - a deep water carbonate basinal facies and a shallow water carbonate shelf facies - are represented. Shape, size and attitude to bedding of Diplotrypa colonies was measured in the field. These data were compared with results gathered from experiments carried out to test the behaviour in a wave tank of representative models of bryozoan colonies. Results have demonstrated a clear environmental partitioning of colonies, and suggest that dome-shaped colonies are more dominent in deep water facies than bell-shaped colonies which occur more abundantly in the shallow water facies. Analysis using bryozoan colonies can provide a useful tool for paleonenvironmental interpretaton.

Eocene Bryozoa from borehole Perwang-1 (Austria).

Kamil Zágorsek
Institut für Paläontologie, GEOZENTRUM, Althanstaße 14, A - 1090 Wien, Austria

Late Eocene sediments with Bryozoa are common in the Alpine-Carpathian region. The bryozoans occur in three major groups of sediments, but bryozoan marl contains the most diverse bryozoan association. The bryozoan marl is the facies, where Bryozoa are the rock forming fossils; the marl contains more than 30 weight percent of bryozoan zoaria. The fauna consists of more than hundred bryozoan species (mostly Cheilostomata of erect growth form), a small amount of echinoid fragments, planktonic foraminifers, and small shells of the brachiopod Argyrotheca, rarely fragments of bivalves.

Dr. Rasser (Institute of Paleontology, Vienna University) has found a rich association of Bryozoa occurring in bryozoan marl during his study of algal limestone from upper Austrian Molasse zone. He has found a rich association of Bryozoa in cores of boreholes Helmberg-1 and Perwang-1. Rohöl AG Vienna drilled the deep wells, and the cores are stored in Pettenbach (Upper Austria), where the samples were collected. Bryozoa from Helmberg-1 are a topic for another study. Here I would like to introduce the Bryozoa from Perwang-1.

Rasser identified the sediments penetrated by borehole as belonging to the Molasse zone. The Austrian Molasse zone is a part of the Alpine - Carpathian Foreland Basin. The transgression of studied sediments was caused by subsidence of the Alpine Foreland Basin during the subduction of the European plate in Late Eocene to Oligocene. The Molasse sedimentation started at Oligocene, when clastic sediments eroded from uplifted Alpine nappe system reach this area. The input of debris was massive, and rapid, and covered all area. Therefore the Eocene sediments of Austrian Molasse zone are only known from deep wells.

Altogether 26 samples have been examined. In 6 samples no Bryozoa occur. The rest samples were disintegrated, washed, and cleaned in ultrasonic. To washed Bryozoans from the samples a new chemical method have to be introduced. The 13 samples of them were cleaned by Quaternary O, and 7 in acetic acid.

By preliminary study more than 90 species were determined, from which more than 70 species belong to Cheilostomatida.

The succession described in Perwang-1 was specific in respect to tectonic repetition of bryozoan marl terminated by Globigerina marls. The most similar associations have been described in Helmberg-1, where however algal limestones terminated the succession. Very similar are the associations from Hybica (Slovakia) and Brendola (Italy) also in similar faunal content. The highest number of common species has localities in Buda marls (Hungary) and association described from borehole Helmberg-1.

Bryozoan marl represents generally the deep and/or cool water association formed perhaps in the place of upwelling of cool water to the shallow tropical environment.

New genera and species of Eocene Bryozoa from Austria and neighbouring countries.

Kamil Zágorsek
Institut für Paläontologie, GEOZENTRUM, Althanstaße 14, A - 1090 Wien, Austria

During the investigation of Eocene Bryozoa in Austria, Hungary and Slovakia 34 new species have been determined and 14 new genera have been proposed.

From Hungary: 13 new species are described in the 12 genera, from which 9 genera are new. All taxa are described in the paper Zágorsek (in press 1).

From Slovakia: 7 new species have been described: Bryochaperia spinella Zágorsek, 1994, Micropora hexagona Zágorsek, 1994, Exidmonea crisiiforma Zágorsek, 1992, Hippomenella bragai, Zágorsek, 1994, Nematifera susannae Zágorsek, 1992, Perigastrella granulata Zágorsek, 1994, Smittipora grandiconis Zágorsek, 1996.

From Helvetic zone (borehole Helmberg-1 - Austria): 3 new species contained in the genus Lagenicella and a new genus have been proposed. The taxa have been described in the paper Zágorsek (in press 2).

From Waschberg zone (Austria) 11 new species in the 7 genera being described in the paper Zágorsek (in press 3). From these 7 genera four new genera have been described.

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