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.     

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.     

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.     

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.     

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.     

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.     

A new Antarctic <Emphasis Type="Italic">Osthimosia</Emphasis> (Bryozoa,Cheilostomata, Celleporidae) with dimorphic zooids

Osthimosia chaotica sp. nov., a new celleporid cheilostome bryozoan, is described from samples collected in the South Shetland Isles and the Antarctic Peninsula. It differs from other Antarctic and Subantarctic species of the genus Osthimosia in the absence of vicarious avicularia, the characteristic development of its peristome and the reduced size of the primary orifice of the ovicelled zooids compared to those of autozooids. The occurrence of sexual polymorphism in the Bryozoa is discussed. The new species lives on laminar and filamentous algae.     

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     

New celleporid (Bryozoa,Cheilostomata) species from Tertiary deposits of western Kachchh,Gujarat, India

Five new bryozoan species (Buffonellaria cornuta, Lagenipora chedopadiensis, Turbicellepora canui, T. naniberensis andT. rostrata) belonging to the family CelleporidaeHINCKS, 1884 are described and illustrated from the Tertiary sequences of western Kachchh, Gujarat, India. The zoaria of these species comprise about 17 percent of total cheilostome bryozoan colonies from Kachchh in the present collection, and those ofTurbicellepora rostrata n. sp. account for over 64 percent of the celleporid specimens. These records of celleporids enrich our knowledge of the fossil occurrence of this group during the Early Miocene in the Indo-Pacific province.     

Wachstums- und Knospungsstrategie vonGrammothoa filifera Voigt & Hillmer (Bryozoa,Cheilostomata, Ob. Kreide)

The genusGrammothoa, growing on the interior walls ofThalassinoides burrows in the Maastrichtian Chalk-tuff, has developed a special growth strategy for spatial competition with other encrusting species which has not been previously recorded in bryozoans. The zoarium consists of auto-zooecia, gynozooecia and chains of smaller zooeciules, the latter forming stolon-like outgrowths from the distal edge of the colony. New areas of substratum are explored and colonized by the growth of these zooeciules. At the branching points of the zooeciules, autozooecia and gynozooecia are budded and may coalesce to form the main part of the colony.     

Larval Behavior and Post-Larval Development in Parasmittina nitida Morphotype B (Bryozoa: Cheilostomata)

Larval behavior and metamorphosis in Parasmittina nitida morphotypeB from the Gulf of Mexico has been studied. The larvae havetwo basic types of movement: (1) a clockwise-counterclockwisemovement about the aboral-oral axis of the lobular larval formresulting in either slow horizontal or rapid vertical movement,and (2) a directed horizontal movement of the creeping larvalform, whereby either the oral lobe is pressed against the substrateor the aboral-oral axis is tilted forward. In both forms, thevibratile plume of the pyriform organ complex extends the leadingedge of the larva. Metamorphosis was observed with Nomarskidifferential interference microscopy in living specimens andwith scanning electron microscopy in fixed specimens. Polypidedevelopment— in particular, the formation and diminutionof the nutritive mass, the differentiation of the polypide rudiment,diaphragm, vestibular glands, operculum, major components ofthe musculature and alimentary canal, and the early stages ofastogenetic growth—is described. The tata ancestrula ofthis species is characterized by a frontal wall calcified distallyto the aperture, which is surrounded by nine erect spines. Thepolypide feeds actively within seven to eight days after theonset of larval attachment and metamorphosis under laboratoryconditions of 22°C.     

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.     

Two new species of Electra (Bryozoa, Cheilostomata) from the Miocene of the Aquitaine Basin, France

Post-Cretaceous examples of Electridae, a primitive family of cheilostome bryozoans, are poorly represented in the fossil record, probably because of their thinly calcified zooids and preference for nearshore environments. Two new electrid species are here described from the Lower Miocene (Burdigalian) of Pontpourquey, Aquitaine, France: Electra triaurata nov. sp. and Electra aquitanica nov. sp. Both species belong to extant species groups, the E. indica and E. biscuta groups, respectively, that presently occur in the Indo-Pacific; both are the only fossil examples of these species groups. Whereas E. triaurata nov. sp. has uniserial colonies, zooids with porous gymnocysts, three flattened spines and basal windows allowing etching of the substrate to produce the trace fossil Leptichnus, E. aquitanica nov. sp. has multiserial colonies and zooids with a proximal gymnocyst bearing 2 to 5 spines.