Bryozoa

The suspension-feeding metazoan subkingdom Lophophorata exhibits characteristics of both deuterostomes and protostomes. Because the morphology and embryology of lophophorates are phylogenetically ambiguous, their origin is a major unsolved problem of metazoan phylogenetics. The complete 18S ribosomal DNA sequences of all three lophophorate phyla were obtained and analyzed to clarify the phylogenetic relationships of this subkingdom. Sequence analyses show that lophophorates are protostomes closely related to mollusks and annelids. This conclusion deviates from the commonly held view of deuterostome affinity.

In 2012 numerous colonies of Pectinatella magnifica (Leidy, 1851) (Bryozoa, Phylactolaemata) were discovered in the reservoir of Esch-sur-Sûre (Luxembourg) fed by the river Sûre. The colonies were particularly abundant in the shallow, warm and nutrient rich water near the riverbank, but some colonies were spotted by divers in the reservoir at a depth of 8-9 m in one site and more than 20 m in another site. There is reliable evidence, that Pectinatella was present, but less conspicuous and not identified as such, in 2011 and possibly already in 2010. P. magnifica was hitherto unrecorded from Luxembourg, but known from a site near the German-Luxembourg border near Nennig (Germany, Saarland) where statoblasts were found in 2001. Besides P. magnifica, the following bryozoan species have been recorded from the reservoir of Esch-sur-Sûre: Plumatella emarginata, P. repens, P. fungosa and Cristatella mucedo.

1. Habitat-forming bryozoans are here defined as extant, heavily-calcified species which regularly attain sizes over 50 mm in three-dimensions and which contribute significantly to benthic habitat structure as living colonies.
2. Records of habitat-forming bryozoans were collated and mapped, together with information about the location, environment, habitat-forming species, the nature and size of the habitat formed, any associated fauna, and relevant threats and/or conservation measures.
3. Records collated here indicated that habitat-forming bryozoans occurred from ~59 N to 77 S, but that they did not occur frequently in the tropics, being found most commonly in temperate continental shelf environments, on stable substrata in places where water movement was relatively fast and consistent.
4. Habitat-forming bryozoans are particularly abundant and diverse in New Zealand, where 27 species, a quarter of which are cyclostomes, provide habitat over hundreds of square kilometres of seafloor. Other areas where they are particularly rich and/or abundant include Antarctica (Weddell, Lazarev and Ross Seas), the North Pacific around Japan, the northern Mediterranean and Adriatic, and along the southern edge of the North Sea, through the English Channel and around the United Kingdom.
5. Large bryozoans provide habitat for diverse associated assemblages, particularly for other bryozoans, molluscs, annelids, arthropods, cnidarians, sponges, echinoderms and macroalgae.
6. Protected areas which include habitat-forming bryozoans occur throughout the distribution of this frequently unrecognized habitat type, but despite this they are prone to damage by anthropogenic impacts including pollution and bottom fishing.

Hara U., Słowakiewicz M. and Raczyński P. (2013) Bryozoans (trepostomes and fenestellids) in the Zechstein Limestone (Wuchiapingian) of the North Sudetic Basin (SW Poland): palaeoecological implications. Geological Quarterly, 57 (3): 417–432, doi: 10.7306/gq.1103 A recently investigated Zechstein Lime stone (Ca1, Wuchiapingian) bryo zoan fauna from the Pol ish part of the South ern Perm ian Ba sin (SW Po land) is dom i nated vol u met ri cally and tax o nom i cally by fenestellids. In to tal six spe cies from five gen-era are rec og nized, com pris ing two spe cies of trepostomes be long ing to Dyscritella Girty, 1911 and four fenestellids at trib-uted to Kingopora Morozova, 1970, Kalvariella Morozova, 1970, Acanthocladia King, 1849 and Spinofenestella Termier and Termier, 1971. The great est biodiversity of the bryo zoans in the Ca1 pro files stud ied is within the slope fa cies where large, fan-shaped and fun nel-shaped re tic u late fenestellid col o nies up to 10 cm high dom i nate. In con trast, bryo zoans in the marginal (prox i mal) parts of the ba sin mostly com prise trepostomes, rep re sented by en crust ing plate-like or coil-shaped col o nies of Dyscritella Girty, and com monly bro ken branched col o nies of Acanthocladia King. The changes in the bi otic com po si tion of the bryo zoans and the pres ence of a dom i nant col ony growth form in the strati graphi cal pro file of the Ca1 re flect the depositional en vi ron ment and wa ter en ergy. These fac tors stim u late the suc ces sive stages of the de vel op ment of the biota and their set tle ment, marked by the rich productid-fenestellid as sem blages typ i cal of the off shore set ting, with the max i mum depth in the mid dle part of the Ca1 in the Grodziec Syncline. The prox i mal tempestites and fore shore fa cies of the up per part of the Ca1 (Leszczyna Syncline) ter mi nate the sed i men tary cy cle of the Ca1, with the rem nant, bro ken bryo zoans of Acanthocladia and fenestellids. The re la tion ship be tween the tax o nomic com po si tion, col ony growth-pat terns, as so ci ated biota, and sed i men tary struc tures points to slow sed i men ta tion rate on slope and ba sin floor of the Ca1 car bon ate plat form. The fenestellids which are dom i nated in the stud ied biota by the re tic u late and pin nate col o nies of Spinofenestella, Kingopora, Kalvariella and Acanthocladia mark a close palaeo geo graphi cal link with the Zechstein (Ca1) bryo zoans of Great Brit ain, Ger many and the south ern Bal tic re gion.

The continental shelf of Rio Grande do Sul (RS) is predominantly composed of unconsolidated sediments with a few hard substrates represented principally by beachrock. In this area there are elongate deposits of shell gravel material which are interpreted as indicators of the palaeo-shorelines. These Pleistocene deposits are overlapped by Holocene sediments (Recent), but are exposed during erosive events caused by extra-tropical cyclones, which provide the mixture of both sediments mainly during autumn and winter. The few studies on bryozoans made in this area previously recorded seven species, one fossil and the other six from Recent fluvial and marine environments. The aim of the present study was to describe the eight most abundant bryozoan species that occur in the inner RS shelf. Of these, four are new records for RS State (Arachnopusia aff. pusae, Hippomonavella brasiliensis, Turbicellepora pourtalesi, and Lifuella gorgonensis), and the other four are new to science (Chaperia taylori, Micropora nodimagna, Cellaria riograndensis, and Exochella moyani).

The transition from uniserial to multiserial forms in the evolution of the bryozoan order Cheilostomata resulted from the change from a proxipetal sequence of development of buds in zooids to a distopetal. Possible morphogenetic mechanisms of this transformation are discussed.

Ernst, A., & May, A., & Marks, S. (2012): Bryozoans, corals, and microfacies of Lower Eifelian (Middle Devonian) limestones at Kierspe, Germany. - Facies, 58: 727-758, 11 figs., 8 tabs.; Erlangen.

http://link.springer.com/article/10.1007/s10347-011-0289-6 ---  Abstract The Lower Eifelian Meinerzhagener Korallenkalk  (= upper Cultrijugatus Beds) at Kierspe, Sauerland,  contains a rich reefal fauna. Eight bryozoan species are  described, two of them are new: the cystoporate Fistuliporella  kierspensis n. sp. and the trepostome Leptotrypella sophiae n.  sp. The bryozoans from the Meinerzhagener Korallenkalk shows distinct similarities to the Lower–Middle Devonian of  Spain (Santa Lucía Formation, Emsian–Eifelian), and to the  Middle Devonian (Eifelian) of Transcaucasia. The coral fauna comprises five tabulate corals and one rugose coral that document a paleobiogeographic relationship between Central  and Eastern Europe and Central Asia. The associated fauna is  represented by brachiopods, ostracods, and echinoderms. The  studied limestones also commonly contain calcimicrobes  represented by three species. The faunal and microfacial  characteristics indicate a shallow marine depositional environment  just above the storm wave base, with a supposed  depth of 20 m, within the photic zone. The nutrient regimewas  at least a mesotrophic. The upper boundary of the Cultrijugatus  Beds coincides with the Chotecˇ-Event that strongly  affected brachiopods, whereas corals and bryozoans were  insensitive to this event. 

Keywords:  Middle Devonian  Germany  Microfacies   Bryozoa  Corals  Brachiopods  Calcimicrobes   Taxonomy  Paleoecology  Paleobiogeography

En principe inoffensifs, certains bryozoaires, marins ou dulcicoles, peuvent néanmoins
créer des nuisances, par exemple, en provoquant des allergies, en colonisant des coques de navires, en obstruant des conduites ou des prises d'eau ou en servant d'hôte intermédiaire à des parasites de poissons d'eau douce. D'autres, bien utiles, contiennent des substances aux potentialités thérapeutiques prometteuses.

The present study considers 88 bryozoan species occurring in freshwater: 69 phylactolaemate and 19 gymnolaemate species. Roughly 49% of these species are confined to one zoogeographical region. The cosmopolitan status of species like Fredericella sultana, Plumatella repens or P. emarginata has to be reconsidered. Among the Phylactolaemata, which are phylogenetically older than the Gymnolaemata, the gelatinous species (Lophopodidae, Pectinatellidae, Cristatellidae) are more primitive than the branching tubular species (Plumatellidae, Fredericellidae).

The breadth of habitat occupied by a species, and the rate at which a species can expand into new habitats has important ecological and evolutionary consequences. Here we explore when extant species of free-living cupuladriid bryozoans expanded into new benthic Caribbean habitats that emerged during the final stages of formation of the Isthmus of Panama. Habitat breadth was estimated using the abundances of over 90,000 colonies in ten cupuladriid species, along with the ecological and sedimentary characteristics of the samples in which they occurred. Data reveal that all species expanded their habitat breadths during the last 6 Myr, but did so at a different tempo. 'Young' species - those that originated after 5 Ma - expanded relatively quickly, whereas 'old' species - those that originated before 9 Ma - took a further 2 Myr to achieve a comparable level of expansion. We propose that, like invasive species, young species are less restrained when expanding their habitat breadths compared to older well-established species. Understanding the mechanism causing this restraint requires further research.

Plastic debris provides long-lasting substrates for benthic organisms, thus acting as a potential vector for their dispersion. Its interaction with these colonizers is, however, still poorly known. This study examines fouling communities on beached, buoyant and benthic plastic debris in the Catalan Sea (NW Mediterranean), and characterizes the plastic type. We found 14 specimens belonging to two phyla (Annelida and Foraminifera) on microplastics, and more than 400 specimens belonging to 26 species in 10 phyla (Annelida, Arthropoda, Brachiopoda, Bryozoa, Chordata, Cnidaria, Echinodermata, Mollusca, Porifera and Sipuncula) on macroplastics. With 15 species, bryozoans are the most diverse group on plastics. We also report 17 egg cases of the catshark Scyliorhinus sp., and highlight the implications for their dispersal. Our results suggest that plastic polymers may be relevant for distinct fouling communities, likely due to their chemical structure and/or surface properties. Our study provides evidence that biofouling may play a role in the sinking of plastic debris, as the most abundant fouled plastics had lower densities than seawater, and all bryozoan species were characteristic of shallower depths than those sampled. More studies at low taxonomic level are needed in order to detect new species introduction and potential invasive species associated with plastic debris.

This study investigates the morphogenesis of eolonies of living bryozoans of the order Cheilostomata and the evolution of the pattern of its development. New data on the morphogenesis of more than ten species of living White Sea bryozoans are presented. The history of the development of colony forms in cheilostome bryozoans from their origin in the Late Jurassie to the present day is studied. A coneept of the evolution of the pattern of colony development, as well as of the development of some zooidal structures, is suggested.
The origin of multiserial colonies from uniserial colonies and ereet colonies from encrusting colonies, the transition from the intrazooidal budding to the zooidal and multizooidal budding, and the reduetion of the intercalary cuticle in the walls of zooids result from two heterochronies in the development of buds (the shift of bud emergence to the earlier stages of development of the matemal zooid and the delay of wall differentiation in buds), which had ensued from selective pressure toward an increase in the colony's growth rate.

In all probability, natural selection began as ancient marine microorganisms were required to compete for limited resources. These pressures resulted in the evolution of diverse genetically encoded small molecules with a variety of ecological and metabolic roles. Remarkably, ...

Floatoblasts collected in Summer 2001 in one of the ponds of St Stephen's Green in the heart of the city of Dublin (Ireland) belonged to the following species: Plumatella casmiana, P. repens, P. emarginata, P. fruticosa, Cristatella mucedo. Concerning P. casmiana this is one of the first records of this species in Ireland.