Little-known Atlantic Cheilostome Bryozoans at the entrance to the Mediterranean

Seven little-known Atlantic species of Bryozoa have been found in the Straits of Gibraltar and are re-described in this paper. For six species their known geographical ranges are significantly increased. They are illustrated by SEM for the first time. New ecological and anatomical data are included. Escharella hexaespinosa Arístegui, 1984 is considered to be a junior synonym of Escharella praealta (Calvet, 1907), n. comb.     

The species of Cellaria (Bryozoa: Cheilostomatida) with large avicularia from West Africa

The three species of Cellaria with large avicularia (the size of an autozooid) known from West Africa have been studied: C. atlantida Cook, C. cookae n. sp. and C. salicornioides Lamouroux. All three are figured by SEM. Cellaria cookae n. sp. is mainly distinguished by its avicularium, with arched and pointed rostrum and mandible and a cryptocyst with a rectangular lyrula. Cellaria atlantida is characterised by its bell shaped Cellaria avicularium. The recognition of C. salicornioides var. normani is considered to be unjustified, as the distinctive character, which is the existence of lateral branching, is only a feature of young colonies and tends to disappear later.     

Taxonomy of the bryozoan genera Oncousoecia,Microeciella and Eurystrotos (Cyclostomata: Oncousoeciidae)

The selection of Tubulipora lobulata Hincks, 1880 Hincks, T. 1880. A history of the British marine Polyzoa, London, , (UK): Van Voorst. [Crossref] , [Google Scholar] as type species when establishing Oncousoecia is interpreted as a deliberate misapplication of a name, the nominal species T. lobulata having been originally described by Hassall in 1841 Hassall, A. H. 1841. Supplement to a catalogue of Irish zoophytes.. Ann Mag Nat Hist., 7: 363–373. [Taylor & Francis Online] , [Google Scholar]. Canu is deemed to have created a new nominal species, Oncousoecia lobulata Canu, 1918 Canu, F. 1918. Les ovicelles des bryozoaires cyclostomes. Études sur quelques familles nouvelles et anciennes.. Bull Soc Géol France, Série 4, 16[for 1916]: 324–335.  [Google Scholar], which is the valid type species of Oncousoecia. Microeciella Taylor and Sequeiros, 1982 Taylor, P. D. and Sequeiros, L. 1982. Toarcian bryozoans from Belchite in north‐east Spain.. Bull Br Mus (Nat Hist), Geol Ser., 37: 117–129.  [Google Scholar] and Eurystrotos Hayward and Ryland, 1985 have each been used to accommodate similar oncousoeciid species with subcircular colonies. The type species of Eurystrotos, Alecto compacta Norman, 1867 Norman, A. M. Report of the committee appointed for the purpose of exploring the coasts of the Hebrides by means of the dredge. – Part II. On the Crustacea, Echinodermata, Polyzoa, and Hydrozoa. Report of the 36^th Meeting of the British Association for the Advancement of Science, Vol. 1866, pp.193–206.  [Google Scholar], has a branching colony‐form and does not differ appreciably from Oncousoecia with which it is here synonymized. Another species, Diastopora suborbicularis Hincks, 1880 Hincks, T. 1880. A history of the British marine Polyzoa, London, , (UK): Van Voorst. [Crossref] , [Google Scholar], previously regarded as being a junior synonym of A. compacta Norman, 1867 Norman, A. M. Report of the committee appointed for the purpose of exploring the coasts of the Hebrides by means of the dredge. – Part II. On the Crustacea, Echinodermata, Polyzoa, and Hydrozoa. Report of the 36^th Meeting of the British Association for the Advancement of Science, Vol. 1866, pp.193–206.  [Google Scholar] (itself a subjective junior synonym of Alecto dilatans Johnston, 1847 Johnston, G. 1847. A history of British zoophytes, London, , (UK): Van Voorst. 2nd edition [Google Scholar]), has a different ancestrular morphology and an unbranched colony‐form. It is here transferred to Microeciella.     

Diversity and taxonomy of intertidal Bryozoa (Cheilostomata) at Akkeshi Bay,Hokkaido, Japan

We found 39 cheilostome species among more than 7000 specimens collected at 10 intertidal sites in rocky habitats along the shore of Akkeshi Bay, eastern Hokkaido Island, Japan. These species are herein described in detail and illustrated by scanning electron microscopy. Nine species (23% of total) are described as new (Electra asiatica, Callopora sarae, Conopeum nakanosum, Cauloramphus cryptoarmatus, Cauloramphus multispinosus, Cauloramphus niger, Stomachetosella decorata, Microporella luellae, and Celleporina minima), and 21 species (54%) are reported for the first time from Japan. Species richness ranged from eight to 29 species per study site. A TWINSPAN analysis showed the species fell into nine groups defined by the local pattern of distribution. A cluster analysis of study sites based on similarity of species composition showed three faunistic groups distributed geographically: in Akkeshi Lake, along the eastern‐central shore of the bay, and at the mouth of the bay. Species richness in estuarine Akkeshi Lake was low, with a species composition very different from the outer bay. Most cheilostomes were found on rock and shell substrata, but uncommonly occurred on concrete walls, algae, hydroids, tubes of polychaetes, other bryozoans, and anthropogenic debris. Of the 39 species found, 33 (85%) contained embryos during the collecting periods, 2–7 June and 3–6 July 2004. The biogeographical composition of intertidal cheilostomes at Akkeshi Bay included species with Arctic‐Boreal (28%), Boreal (59%), and Boreal‐Subtropical (13%) distributions. The overall species richness of intertidal cheilostomes was two‐thirds that documented intertidally in a comparable study at Kodiak, Alaska, a locality 15° higher in latitude. We attribute the lower richness at Akkeshi to differences in the nearshore marine environment between the two localities.     

New species of cheilostomate Bryozoa from Antarctica and the Subantarctic southwest Atlantic

Fourteen new species of Bryozoa Cheilostomatida are described in the genera Chaperiopsis, Dakariella, Plesiothoa, Celleporella, Galeopsis, Osthimosia, Reteporella, Rhynchozoon and Turritigera. Acanthophragma gen. nov. is introduced for A. polaris sp. nov., and Tracheloptyx gen. nov. for T. antarctica sp. nov.     

Recent and fossil species of Characodoma Maplestone, 1900 (Bryozoa) from the Mediterranean with description of two new species

Three species of Characodoma Maplestone, 1990 from the Mediterranean are discussed here. Two, C. rostratum and C. reclinatum are described as new from Pleistocene bathyal sediments of Southern Italy. The third, C. mamillatum (Seguenza, 1880) was already known from Tertiary-to-Quaternary sediments of Southern Italy. It has been recognized as the senior synonym of C. bifurcatum (Waters, 1918). Stratigraphical, geographical and ecological distributions of all the species are discussed. Morphological studies, principally of C. mamillatum, provide useful information about the life habit of these species.     

Rissoidae (Mollusca: Gastropoda) from northeast Atlantic seamounts

The gastropod family Rissoidae is revised at the species level for the Lusitanian seamounts, situated between Portugal and Madeira, and the Meteor group of seamounts, situated south of the Azores in the northeast Atlantic Ocean. Based on material obtained by dredging and trawling, 48 species are reported, of which 30 are described as new. There is very little overlap between the assemblages found on both groups of seamounts, with only two shared species. On the Lusitanian seamounts, 24 species were collected. Seven species (six with planktotrophic development) are shared with the mainland shelf or slope and are represented in low numbers. Eleven species are endemic to this seamount group as a whole and of these, three account for 75% of individuals. Of the species not shared with the mainland, only one is found on the four seamounts, eight (three new) are found on two or three seamounts and/or neighbouring islands, and six (all new) are endemic to a single seamount. On the Meteor group, 26 species were found, of which five are shared with the Azores and 20 (all new) are endemic to the seamount group as a whole. Most species are found on only two or three seamounts, whereas nine species are endemic to only one of the seamounts, and of these five are concentrated on Atlantis seamount. Eight endemic species of the Meteor group included in Porosalvania n. gen. have very different shapes and occupy discrete bathymetric intervals, but are best interpreted as a local radiation originating from a relatively old colonization of this seamount group. The endemic species, and among them the successful ones, all have a paucispiral protoconch denoting non‐planktotrophic development. As in the Macaronesian archipelagos, the Rissoidae are the most species‐rich molluscan family on the northeast Atlantic seamounts.     

Chaperiopsis cristata (Busk, 1884) (Bryozoa,Cheilostomata) is Chaperiopsis annulus (Manzoni, 1870). The occurrence of this species from the European Atlantic coast

We propose that Chaperiopsis annulus (Manzoni, 1870) is conspecific with C. cristata (Busk, 1884), and that C. annulus has priority. We also record this species for the first time from the European Atlantic coast.     

Two new genera of Bryozoa (Calloporidae) from New Zealand

Two new genera of the bryozoan family Calloporidae are described from New Zealand. The first, Leptinatella, is introduced for L. gordoni n. sp., specimens of which have been referred in the past to Watersia militaris (Waters) but are distinct from this species, which is a phase of the cribrimorph Corbulipora tubulifera (Hincks). The second genus, Bryocalyx, is introduced for B. cinnameus n. sp., which has small, conical colonies anchored by rhizoids. Another species of Bryocalyx is known from a few fragments only: and has also been referred in the past to Watersia sp. It is briefly discussed, but left unnamed here.     

Cheilostomata (Bryozoa) from the South Atlantic

Two new genera Monitus gen.nov. and Cuckoldillo gen.nov., a new species of each of Scyphax, Rhyscotus, Filippinodillo, Merulana, Myrmecodillo, and three new species of Acanthodillo are described from Australia. The unavailability of the name Pseudodiploexochus and the confusion concerning the diagnoses of the genera Merulana Budde-Lund and Cubaris Brandt is noted. The synonomy of Merulana and Pyrgoniscus is discussed.     

The Cheilostomate Bryozoa (Bryozoa: Cheilostomatida) collected by the Spanish 'Antartida 8611' Expedition to the Scotia Arc and South Shetland Islands

The Cheilostome Bryozoa of the ‘Antartida 8611’ Expedition, collected by the Spanish Oceanographic Institution (Instituto Espanol de Oceanografia, IEO) during the Antarctic summer 1986–87 are listed. This expedition collected abundant material of benthic invertebrates at many stations in the Scotia Sea archipelagos and South Shetland Islands, of which 70 yielded Cheilostomate Bryozoa. Of 85 species found, 32 have been collected in areas where they were not previously known. Twenty of them are recorded north of their known limit of distribution and two recorded south. Most of these species are cited for the first time for the Scotia Arc, thus supporting the generally admitted homogeneity of the Antarctic fauna. The presence of Arachnopusia monoceros in the Southern Ocean is confirmed; a previously unknown variability in the colony shape of Kymella polaris is reported and the ovicell of Exochella umbonata is described. In addition, four species have been proposed as new to science, three of them, belonging to the genera Cellaria, Klugerella and Hippomonavella, described in the present work and one, Macropora georgiensis, included in a previous work. Together with the discussion of the new species of Klugerella, the specific composition of this genus is updated, with the assignation of Membraniporella aragoi (Audouin) and Membraniporella marcusi Cook to Klugerella. The examination of the inner side of the orifice and the frontal wall of three species of Hippomonavella reveals that the frontal is at least partially umbonuloid and that this genus is better accommodated in the family Bitectiporidae MacGillivray, 1895 than in Smittinidae Levinsen, 1909. Se presenta un listado de los Briozoos Queilostomados obtenidos en la campana ‘Antartida 8611’ del Instituto Espanol de Oceanografia (IEO) durante el verano antartico de 1986-87. Esta expedicion recolecto un abundante material de invertebrados bentonicos en un alto numero de estaciones de los archipielagos del arco del Scotia y las islas Shetland del Sur, de las cuales 70 contenian briozoos. De las 85 especies encontradas, 32 se han recogido en areas en las que no eran conocidas previamente. De ellas, 22 aumentan hacia el norte su limite de distribucion y dos hacia el sur. Muchas de estas especies se citan por primera vez en el arco del Scotia, corroborando la generalmente admitida homogeneidad de la fauna antartica. La presencia de Arachnopusia monoceros en aguas antarticas, que habia sido puesta en duda, se confirma; se describe una variabilidad antes no conocida de la forma colonial de Kymella polaris, asi como la ovicela de Exochella umbonata, que no habia sido encontrada. Ademas, cuatro especies se han propuesto como nuevas para la Ciencia, de las que tres, pertenecientes a los generos Cellaria, Klugerella e Hippomonavella, se describen en este trabajo, y la otra, Macropora georgiensis, se ha incluido en una revision del genero publicada anteriormente. En la discusion de la nueva especie de Klugerella, se actualiza la composicion especifica de este genero, anadiendo al mismo Membraniporella aragoi (Audouin) y Membraniporella marcusi Cook. Se pone de manifiesto que la pared frontal de Hippomonavella es al menos parcialmente umbonuloide y, dadas las caracteristicas de dicha pared y del orificio, se propone que el genero Hippomonavella esta mejor situado en la familia Bitectiporidae MacGillivray, 1895 que en Smittinidae Levinsen, 1909.     

Species of Arachnopusia (Bryozoa: Cheilostomata) collected by discovery investigations

Eighteen species of the cheilostome bryozoan genus Arachnopusia Jullien are described from Antarctic, Subantarctic and southern cold temperate localities. Eleven species are considered to be new to science. The morphology of Arachnopusia species is discussed, with particular reference to features of taxonomic value, and the zoogeography of the genus is considered briefly.     

Notes on astogeny of some Petraliellidae (Bryozoa) from Australia

Members of the bryozoan family Petraliellidae share the capacity to develop basal rhizoids, which anchor the unilaminar, semi-repent parts of the colonies above the substratum, and enable them to overgrow other, competing sessile forms. Little is known of the larval behaviour and settlement, or the early astogeny of species. Ancestrulate colonies of the Australian Tertiary lunulitiform species Smittia biincisa are referred to the genus Riscodopa, and together with Riscodopa paucipora sp. nov. are described and compared with the Recent species R. cotyla and R. parva from New Zealand, and with R. hyalina sp. nov. from New South Wales, Australia. All the Recent species are known to develop basal rhizoids, and an early astogeny similar to that of many other small, rooted bryozoans, comprising the post-metamorphosis development of a binary complex, including rhizoid and feeding elements, is inferred for Riscodopa. Observations on living Hippopetraliella magna from Queensland suggest that both the ancestrular morphology and early astogeny show a capacity for semi-repent growth, even though they do not include rhizoid development. Larvae metamorphose without direct attachment, and the ancestrula develops elongated, partially calcified supporting processes, which raise the early stages of growth above the substratum. A similar kind of ancestrula has been found in preserved specimens of Mucropetraliella ellerii.     

Amphiblestrum Gray, 1848 (Bryozoa Cheilostomatida) from the Atlantic-Mediterranean area,with description of a new species

Several species, belonging to the genus Amphiblestrum Gray from the Atlantic-Mediterranean area are discussed. One species is described as new: A. frigidum sp. n., from Lower Pleistocene sediments of the Mediterranean area and from the Recent Northern Atlantic. Systematic affinities among species are discussed together with geographical, ecological and stratigraphical distributions. The climatic-palaeoclimatic significance of some species is stressed: A. lyrulatum and the fossil A. spaeleus and A. intermedius seem to be warm-temperate species whereas all the others are cool, boreal or boreal-arctic species. A. flemingi and A. frigidum sp. n., both Recent Northern Atlantic species known from Würmian submerged sediments and/or Lower Pleistocene outcrops of the Mediterranean area are considered as Boreal Guests.