Systematic notes on some British Ascophora (Bryozoa: Cheilostomata)

A review of the British ascophoran cheilostomes has revealed several instances of synonymic confusion, and necessitated the introduction of two new generic names. Porelloides gen. nov. is instituted for two species formerly included in Porella , with P. laevis (Fleming) as type species, and Phaceostachys gen. nov. is introduced for Lepralia spinifera Johnson. Smittoidea amplissima sp. nov. was hitherto not distinguished from Smittina landsborovii (Johnston). Porella minuta (Norman), reported from localities as far afield as the western Mediterranean and the Canadian Arctic, is shown to comprise two species, and the northern records are here attributed to P. alba Nordgaard. Exharella labiosa (Busk) and E. klugei sp. nov. (=E. ventricosa var. peristomata Kluge) are redescribed, and E. laqueata and E. abyssicola are discussed. The case for retaining Cellepora Linnaeus is argued and Lepralia quincuncialis Norman is referred to Buskea Heller.     

Some Antarctic and sub-Antarctic species of Smittinidae (Bryozoa: Cheilostomata)

Twenty-six species of Bryozoa, in the ascophoran cheilostome family Smittinidae Levinsen, 1909, are described from Antarctic and sub-Antarctic localities. Fourteen species are considered to be new to science. Aspericreta gen. nov. is introduced for Smittina crassatina Waters, 1904, and Platychelyna gen. nov. for Cellarinella planulata Hayward, 1980.     

Colony–Substratum Relations in Scrupocellariidae (Bryozoa, Cheilostomata)

In the Bryozoa in general the colony is attached by means of the primary zooid, the ancestrula, which is permanently cemented to the substratum. The attachment is brought about, in the marine bryozoans, by the larva everting its interior sac into a basal adhesive disc secreting a thin layer of hardening mucus. In Scrupocellaria reptans no adhesive disc was found. The metamorphosing larva is fixed to the substratum by a column of loose, sticky secretion. This primary fixation is ephemeral and replaced by a secondary, permanent fixation by one pair of rootlets. Thus, the ancestrula body proper and the colony arising from it become permanently free from the substratum but anchored to it by rootlets, the primary pair and series of secondary rootlets. This unique and certainly secondarily evolved type of attachment is apparently realized in the Scrupocellariidae in general, to a more or less perfect degree. It appears as one of several possible models to meet efficiently with environmental disturbances.     

Systematic studies on some Antarctic and sub-Antarctic Ascophora (Bryozoa: Cheilostomata)

Twenty-two species of ascophoran cheilostome Bryozoa are described and figured from Antarctic and sub-Antarctic localities. Ten new species are described in the genera Exochella, Buffonellodes and Hippadenella. Ralepria gen. nov. is introduced for Ralepria conforma sp. nov., and Trilochites gen. nov. is introduced for Escharoides biformata Waters, 1904. Five species described by Jullien (1888) and Calvet (1909) are redescribed following re-examination of type specimens.     

Systematic notes on some Antarctic Ascophora (Bryozoa, Cheilostomata)

Nine new species of ascophoran cheilostome Bryozoa are described from Antarctic localities. Five species are considered to be new to science ( Smittina favulosa, Smittina diffidentia, Smittoidea pugiuncula, Escharella mamillata, Fenestrulina antarctica ), while four others have been previously recorded under other names ( Smittoidea malleata, Escharella watersi, Lacerna watersi, Hippothoa belgica ). Escharella crozetensis Waters, formerly recorded from Antarctica, is considered to be limited to the Kerguelen region of the South Indian Ocean.     

Some Antarctic and sub-Antarctic species of Celleporidae (Bryozoa, Cheilostomata)

Sixteen species of cheilostome Bryozoa, within the family Celleporidae Busk, 1852, are reported from Antarctica and the sub-Antarctic south-west Atlantic. Nine new species are described in the genera Osthimosia Jullien, 1888, Celleporina Gray, 1848 and Turbicellepora Ryland, 1963. Spigaleos gen. nov. is introduced for Cellepora horneroides Waters, 1904.     

Growth aspects of Flustra foliacea(Bryozoa, Cheilostomata) in laboratory culture

Flustra foliacea is a cheilostome marine bryozoan which, after initial horizontal growth during the first year, changes to erect growth thereafter. Appraising this slow-growing species for biotechnological use, required the development of cultivation methods for economical biomass production. Vegetative reproduction via cuttings, as employed in the horticulture of various plants, was tested. Fronds of F. foliacea were cut into pieces (10–150 mg fresh weight) and fixed in longitudinally cut silicon tubes. Bryozoa were fed with a mixture of Isochrysis galbana, Dunaliella tertiolecta and Cryptomonas sp. yielding growth rates of 0.3% ± 0.02 day^?1of the initial fresh weight. Growth of the colony occurred firstly at the original growth margin, but later also at the transections, including the side fixed in the silicon tube, opposite to the growth margin. After three months of growth, the two layers of zooids split at the growth margin, forming two monolayers. This growth feature, not described previously for Flustra foliacea,was observed under experimental and natural conditions, and is interpreted as the beginning of one type of ramification. According to our findings, vegetative reproduction of F. foliacea under laboratory conditions is possible and might be an alternative to natural resources regarding biomass of this species.     

Body wall morphology of Pentapora foliacea (Ellis and Solander) (Bryozoa,Cheilostomata)

The ascophoran Pentapora foliacea was studied from epoxy sections of skeletal and soft (hard-soft) tissues. The basal wall is double, indicating the colony grew as two independent layers, back to back. The structure of the vertical walls and interzooidal communication organs indicates that zooids were budded in the usual way as in most encrusting cheilostomes. Secondary layers of the frontal wall are of acicular aragonite. The ovicell develops as a flattened cuticular bladder in early ontogeny; the aragonitic layer of the frontal wall later engulfs it. A median vesicle, an evagination of the vestibular wall, is present but the eggs may be supplied with sufficient yolk to nurture the embryo. The overall ovicell structure is similar to that of hyperstomial ovicells in other cheilostomes.     

Doryporella smirnovi sp. nov. (Bryozoa: Cheilostomata) and its impact on phylogeny and classification

A new species of Doryporella, D. smirnovi sp. nov. is described from the area of the Commander Islands. Inclusion of this species in a revised phylogenetic analysis of Doryporella and its relatives permits the recognition of a clade comprising Doryporella and Doryporellina. This clade is accorded family-level status as the Doryporellidae fam. nov., thereby removing Doryporella (and Doryporellina) from the large and paraphyletic Calloporidae.     

The Recent species of Adeonella (Bryozoa: Cheilostomata) including descriptions of fifteen new species

The genus Adeonella Busk (1884) comprises 41 species, 15 of which are considered to be new to science. Adeonella lichenoides (Lamarck) is regarded as the senior synonym of A. platalea (Busk) (= A. polymorpha Busk), the type species of the genus. Adeonella is distributed throughout the Indo-West Pacific realm, the Mediterranean, and the South Atlantic Ocean. Its highest diversity is found off the east coasts of southern Africa. Thirty-one species (15 new to science) are described and illustrated, morphology and geographical distribution are discussed and a key is provided to all recognized species.     

Sexual reproduction in Epistomia bursaria (Bryozoa: Cheilostomata), an endozooidal brooder without polypide recycling

Epistomia bursaria L. is unusual amongst cheilostomes in that there is only one polypide generation per autozooid, together with endocoelomic embryonic brooding and larval viviparity. This combination, which gives the minimum possible fecundity of one larva per gynozooid is only known for one other cheilostome species, the majority of the rest being extracoelomic ovicellate brooders with polypide recycling. The greater fecundities exhibited by ovicellate and non-brooding recyclers may offset the smaller degree of protection afforded by these reproductive strategies.
Spermatogenesis and oogenesis are examined ultrastructurally. Whereas spermatogenesis is similar to that of other cheilostomes studied previously, oogenesis is very different. The egg at maturity is small and alecithal. Evidence suggests that endozooidal self-fertilization occurs. Whereas nutrient for spermatogenesis and oogenesis is probably intrazooidal in origin, that for embryogenesis is derived inter-zooidally.
It is suggested that the combination of endocoelomic brooding, larval viviparity and one polypide generation may be a primitive feature from which recycling and extracoelomic brooding may have evolved.     

North-east Atlantic and Mediterranean species of the genus Buffonellaria (Bryozoa, Cheilostomata): implications for biodiversity and biogeography

In this study we revise the cheilostome bryozoan genus Buffonellaria Canu & Bassler, 1927 and its Mediterranean and north-east Atlantic species, thereby addressing several existing problems. First, a lectotype for the type species, Buffonellaria divergens (Smitt, 1873) from Florida, is chosen, which proves to be distinct from the European species. Second, the two hitherto established north-east Atlantic species [ Buffonellaria nebulosa ( Jullien & Calvet, 1903 ) and Buffonellaria porcellanum Arístegui Ruiz, 1987], are redescribed, which were poorly documented until now. Third, close inspection of material, collected from Spitsbergen to tropical West Africa, using scanning electron microscopy reveals that the actual number of species, all previously referred to either B. divergens or Stephanosella biaperta (Michelin, 1848), is distinctly greater in the north-east Atlantic than has been previously acknowledged. As a result, seven new species are introduced ( Buffonellaria acorensis sp. nov. , Buffonellaria antoniettae sp. nov. , Buffonellaria arctica sp. nov. , Buffonellaria harmelini sp. nov. , Buffonellaria jensi sp. nov. , Buffonellaria muriella sp. nov. , and Buffonellaria ritae sp. nov. ), whereas two are left in open nomenclature. With the increase in number of species, the extremely broad geographical range of distribution assumed for B. divergens breaks down to numerous restricted areas. However, although most species have only been reported from a single location, B. arctica sp. nov. seems to have a fairly wide distribution in the Arctic region.  © 2008 The Linnean Society of London, Zoological Journal of the Linnean Society , 2008, 152 , 537–566.     

Early Colony Development in Aetea (Bryozoa)

External structures on the erect parts of zooids of Aetea havebeen demonstrated to be brood chambers by observation of release,settlement and metamorphosis of larvae from the chambers. Theancestrula is smaller than, but very similar to succeeding zooidsin the primary zone of astogenetic change, which do not showtubular connections. Sections through brood chambers and zooidsshow that part of the brood chamber wall may be slightly calcified.Brood chambers appear to be products of the external zooid walland not diverticula derived from the tentacle sheath.     

Epibiont foraminifera of Sertella frigida (Waters) (Bryozoa, Cheilostomata) from Terranova Bay, Ross Sea, Antarctica

Several arenaceous and calcareous foraminifera epibionts of Sertella frigida (Waters) (Bryozoa, Cheilostomata), collected in Terranova Bay during the 1989–90 Italian Antarctic expedition, were studied. Arenaceous species, such as Psammosphaera fusca Schulze f. adhearescens Rhumbler, Haplophragmoides canariensis d'Orbigny, Portatrochammina antarctica (Parr), and Trochammina arctica Hedley, Hurdle and Burdett, are a conspicuous component of the epifaunal community. The calcareous foraminifers encrusting S. frigida are mostly represented by Cibicides refulgens Montfort and Rosalina globularis d'Orbigny. Foraminifera were found only in the basal part of the bryozoan colonies. The presence of many juveniles provided evidence that foraminifers were reproducing at the time of sampling. Psammosphaera fusca f. adhaerescens was found exclusively inside the zooids of S. frigida. The large number of individuals associated with the bryozoan suggest that P. fusca f. adhaerescens finds optimum conditions (shelter, food, and grains for shell building) for growth inside the zooids of S. frigida. The other species occurred most commonly adhered to the trabeculae or to the zooid orifices of S. frigida. An elevated position offers a better chance to catch food particles from the overlying water column. Foraminifers could benefit also from bryozoan feeding currents. The availability of resuspended organic material could provide a more consistent source of food in a highly seasonal oligotrophic environment. Received: 8 February 1995/Accepted: 30 June 1996