山东半岛近岸水域铃苔虫属一新种（苔藓动物门：唇口目：马孔苔虫科）

双型铃苔虫,新种Ｃｏｄｏｎｅｌｌｉｎａ ｂｉｆｏｒｍｉｓ ｓｐ．ｎｏｖ．群体双型,被覆－直立。单层群体个虫细狭;口下鸟头体小;颚骨圆三角形、半椭圆形。双层群体个虫较宽;口下鸟头体大,颚骨均呈匙形,其末端部分均膨胀。新种双层群体个虫的口下鸟头体颚骨形态和卵胞表面孔饰与口盖铃苔虫Ｃｏｄｏｎｅｌｌｉｎａ ｏｐｅｒｃｕｌａｔａＭａｗａｔａｒｉ,１９５６有些相似,但新种在群体生长方式以及在室口形态、口盖表面     

中国南部水域膜孔苔虫属一新种：苔藓动物门：唇口目：膜孔苔虫科

连壁膜孔苔虫Ｍｅｍｂｒａｎｉｐｏｒａｃｏｎｊｕｎｃｔｉｖａｓｐ．ｎｏｖ．群体被覆、单层。相邻个以隆起的个虫墙缘为界,无室间沟。横壁孔室单孔型,由大、中、小三种单孔组成。侧壁孔室多孔型,由一列大孔和列小孔组成。新种个虫一般形态与大室孔苔虫Ｍｅｍｂｒａｎｉｐｏｒａｇｒａｎｄｉｃｅｌｌａ的单层群体相似,但其权成相邻个虫的界限和体壁孔室的结构及排列方式与大室膜孔苔虫有显著区别。     

Révision systématiquedu genre Steginoporella smitt, 1873 (Bryozoa Cheilostomata)

Systematic revision of the genus Steginoporella: until now about eighty species were described. Only twenty recent species and thirty-four fossil ones are maintained. Several species and subspecies are new.The main interest of this revision is to establish a biostratigraphical scale: the settlement of this scale is based on the known stratigraphical distribution and on an attempt of phylogeny.The second advantage is ecological: all recent species live in marine tropical environment. The Steginoporella are good paleoecological indicators.At last, the establishment of a paleobiogeography, even incomplete and not definitive, allows to understand more easily recent distribution of Steginoporella connected with the great events of earth evolution.     

Comparative anatomical study of internal brooding in three anascan bryozoans (Cheilostomata) and its taxonomic and evolutionary implications

The anatomical structure of internal sacs for embryonic incubation was studied using SEM and light microscopy in three cheilostome bryozoans-Nematoflustra flagellata (Waters,1904), Gontarella sp., and Biflustra perfragilis MacGillivray, 1881. In all these species the brood sac is located in the distal half of the maternal (egg-producing) autozooid, being a conspicuous invagination of the body wall. It consists of the main chamber and a passage (neck) to the outside that opens independently of the introvert. There are several groups of muscles attached to the thin walls of the brood sac and possibly expanding it during oviposition and larval release. Polypide recycling begins after oviposition in Gontarella sp., and the new polypide bud is formed by the beginning of incubation. Similarly, polypides in brooding zooids degenerate in N. flagellata and, sometimes, in B. perfragilis. In the evolution of brood chambers in the Cheilostomata, such internal sacs for embryonic incubation are considered a final step, being the result of immersion of the brooding cavity into the maternal zooid and reduction of the protecting fold (ooecium). Possible reasons for this transformation are discussed, and the hypothesis of Santagata and Banta (Santagata and Banta1996) that internal brooding evolved prior to incubation in ovicells is rejected.     

New taxa of Japanese and New Zealand Eurystomellidae (Phylum Bryozoa) and their phylogenetic relationships

As presently recognized, the small cheilostome bryozoan family Eurystomellidae (superfamily Catenicelloidea) comprises just two genera: Eurystomella Levinsen, 1909 , with three Recent species, and Selenariopsis Maplestone, 1913 ; with one Recent and two fossil species. Within Eurystomella sensu lato , colonies range from uni-/biserial to multiserial and the smooth gymnocystal frontal shields of zooids may be entire or have one to several large foramina. Here we describe seven new Recent species of encrusting eurystomellids from New Zealand and Japan. Including species of Selenariopsis , a cladistic analysis was carried out on 11 eurystomellid species and five outgroup species, the latter representing the families Cribrilinidae, Euthyroididae, Petalostegidae, and Catenicellidae. The results of the analysis support restricting Eurystomella to multiserial species with large frontal foramina, median suboral sutures, and basal pore-chambers. Two new genera, both with imperforate frontal shields and uniporous mural septula, are segregated from Eurystomella : uni-/biserial Zygopalme , with a median suboral suture and accssory perforations in the ovicellular kenozooid, and multiserial Integripelta , lacking the suture and accessory perforations.  © 2002 The Linnean Society of London, Zoological Journal of the Linnean Society , 2002, 136 , 199–216.     

Late Campanian to late Maastrichtian bryozoans encrusting on belemnite rostra from the Aktolagay Plateau in western Kazakhstan

Twenty species belonging to fifteen genera of cyclostome and cheilostome bryozoans encrusting belemnite rostra are described from the late Campanian to Maastrichtian of the Aktolagay Plateau, in western Kazakhstan. Due to the moderate to poor preservation of the material, only four cheilostome species are identified down to the species level: Wilbertopora? besoktiensis (Voigt, 1967), ‘Aechmellina’ stenostoma Voigt, 1930, and two new species, ‘Aechmellina’ viskovae and Cheethamia aktolagayensis. All remaining species are left in open nomenclature. Type material of Wilbertopora? besoktiensis from the early Maastrichtian of the Mangyshlak Peninsula in Kazakhstan, has been re-examined. Palaeobiogeographical and implications are discussed. Cheilostomes slightly dominated over cyclostomes in the Aktolagay Plateau fauna encrusting on belemnites in terms of diversity. The dominant colony forms observed were spots and sheets.     

Diversity of brood chambers in calloporid bryozoans (Gymnolaemata,Cheilostomata): comparative anatomy and evolutionary trends

Comparative anatomical studies of 12 species from 10 genera (Callopora, Tegella, Amphiblestrum, Parellisina, Corbulella, Crassimarginatella, Valdemunitella, Bryocalyx, Concertina, Cauloramphus) belonging to one of the largest and most diverse bryozoan taxa, the Calloporidae, and one species from the genus Akatopora belonging to the related taxon Antroporidae, were undertaken to elucidate the morphological diversity of brooding structures and to recognize main trends in their evolution. Most of the species studied possess ovicells (specialized brooding receptacles) formed by the distal and maternal (egg-producing) autozooids. The distal zooid can be an autozooid, a vicarious avicularium or a kenozooid. The calcified protective hood (ooecium) is an outgrowth from the distal zooid. Hyperstomial or prominent ovicells are most common. They were found in species of the genera Callopora, Tegella, Amphiblestrum, Parellisina, Corbulella, Bryocalyx and Concertina. Subimmersed ovicells were found in Valdemunitella, and immersed ovicells in Crassimarginatella and Akatopora. Cauloramphus has an internal brooding sac and a vestigial kenozooidal ooecium, budded by the maternal zooid. Based on the structure of the brooding organs, the following evolutionary trends can be recognized within the group: (1) reduction of the distal (ooecium-producing) zooid, (2) immersion of the brooding cavity correlated with a reduction of the ooecium and ooecial vesicle and with changes in the ovicell closure and the structure of the brood chamber floor, (3) reduction of the calcification of the ectooecium, and (4) transition from bilobate to entire ooecium. The trend towards immersion of the brooding cavity could have evolved repeatedly within the Calloporidae. Transition from bilobate to entire ooecium is characteristic of the related taxon Cribrilinidae, showing a good example of parallel evolution of the ooecium in two closely related clades. Possible causes for the transformations described are discussed.     

G protein-linked receptors and induction of metamorphosis in Bugula stolonifera (Bryozoa)

Abstract. Induction of metamorphosis in larvae of the marine bryozoan Bugula stolonifera was examined for potential roles of G protein-linked cell-surface receptors. Two compounds that modulate components of the G protein system were tested in a bath-applied experimental design over concentrations of 10⁻⁸ to 10⁻³ M, plus a seawater control, and 2 controls to assess metamorphic competence (10 mM excess KCl and a biofilmed surface). The G protein activator Gpp[NH]p and the G protein inhibitor GDP-β-s did not affect rates of metamorphosis, under the conditions tested. We found no evidence that G protein-linked cell-surface receptors are the receptors of the metamorphic cue in this species. This negative finding parallels reports on a gastropod and a polychaete; by contrast, G proteins are involved in metamorphic induction in several cnidarians, a nematode, and barnacles. Thus, as no single model can account for induction across phyla, our results may serve to focus attention on identifying possible roles of the other 2 major classes of cell-surface receptors in triggering metamorphosis in B. stolonifera and other invertebrates.     

One hundred million years of competitive interactions between bryozoan clades: asymmetrical but not escalating

Direct evidence of competition is seldom available from the fossil record. Overgrowth relationships of encrusting marine organisms constitute an exception but have previously been reported in only temporally and geographically local occurrences. Results of overgrowths between members of two bryozoan clades, the Cyclostomata and the Cheilostomata, have been compiled for faunas distributed through the past 100 Myr. The cheilostomes have consistendy out-competed the cyclostomes, with approximately 66% overgrowdi success through the entire interval. This difference in success in direct interactions along with the Mid-Cretaceous rapid radiation of cheilostomes is interpreted as a factor in the Mid- to Late Cretaceous reversal from the previous diversification to stasis or gradual decline of cyclostome diversity.     

A multi-locus analysis of phylogenetic relationships within cheilostome bryozoans supports multiple origins of ascophoran frontal shields

Phylogenetic relationships within the bryozoan order Cheilostomata are currently uncertain, with many morphological hypotheses proposed but scarcely tested by independent means of molecular analysis. This research uses DNA sequence data across five loci of both mitochondrial and nuclear origin from 91 species of cheilostome Bryozoa (34 species newly sequenced). This vastly improved the taxonomic coverage and number of loci used in a molecular analysis of this order and allowed a more in-depth look into the evolutionary history of Cheilostomata. Maximum likelihood and Bayesian analyses of individual loci were carried out along with a partitioned multi-locus approach, plus a range of topology tests based on morphological hypotheses. Together, these provide a comprehensive set of phylogenetic analyses of the order Cheilostomata. From these results inferences are made about the evolutionary history of this order and proposed morphological hypotheses are discussed in light of the independent evidence gained from the molecular data.Infraorder Ascophorina was demonstrated to be non-monophyletic, and there appears to be multiple origins of the ascus and associated structures involved in lophophore extension. This was further supported by the lack of monophyly within each of the four ascophoran grades (acanthostegomorph/spinocystal, hippothoomorph/gymnocystal, umbonulomorph/umbonuloid, lepraliomorph/lepralioid) defined by frontal-shield morphology. Chorizopora, currently classified in the ascophoran grade Hippothoomorpha, is phylogenetically distinct from Hippothoidae, providing strong evidence for multiple origins of the gymnocystal frontal shield type. Further evidence is produced to support the morphological hypothesis of multiple umbonuloid origins of lepralioid frontal shields, using a step-wise set of topological hypothesis tests combined with examination of multi-locus phylogenies.