Gender of the genus Botrylloides Milne Edwards (1841) [Tunicata: Ascidiacea].

Milne Edwards (1841) introduced Botrylloides listing species with both feminine and neuter word endings. The International Code on Zoological Nomenclature, however, indicates that generic names ending -oides should be masculine unless the introducing author unambiguously indicated a different gender. The resulting uncertainty has caused prolonged confusion over the correct gender of Botrylloides. It is here affirmed that Milne Edwards did not provide a clear indication of gender and the general rule of the International Code applies: Botrylloides has masculine gender. The type species is B. rotifer Milne Edwards (its ending corrected from the feminine B. rotifera).

First occurrence of the non-native bryozoan Schizoporella japonica Ortmann (1890) in Western Europe.

Schizoporella japonica Ortmann was described from Japan but was subsequently introduced on Pacific oysters to the Pacific coast of North America, where it is now well established. In this paper we record it for the first time in European waters. The initial discovery was in a marina at Holyhead, North Wales, in July 2010 but S. japonica has since been observed abundantly in the Orkney Islands (from May 2011) and, subsequently, at other localities in northern Scotland. Introduction seems most likely to have been on an ocean-going vessel. The British material is here fully described and illustrated with SEMs and colour photographs; some unusual characters are discussed. Unlike other recently introduced bryozoans, S. japonica is a cold-water species and its breeding season in Britain extends through the winter. Extensive confusion between this and other species of Schizoporella on the west coast of Canada and the USA led us to make thorough morphometric comparisons between the species concerned (Schizoporella unicornis (Johnston in Wood), Schizoporella errata (Waters) and Schizoporella pseudoerrata Soule, Soule and Chaney). Zooid size in cheilostomate bryozoans is variable and often an unreliable character for species separation but shape (and therefore ratios between variables, which are independent of size) are often valuable: S. japonica zooids have a much greater length:width ratio than the other species. Density of frontal pseudopores provides a useful discriminatory character. Schizoporella unicornis, repeatedly reported in error from the Pacific coast of North America, does not occur there; it is a European species. Full comparisons are made between S. japonica and S. unicornis for European identification and between S. japonica, S. errata and S. pseudoerrata (which are also illustrated) for North American localities.

Carcinoecium-forming Epizoanthus [Hexacorallia: Zoantharia] and the biology of E. papillosus in the eastern Atlantic, with special reference to the cnidom.

Epizoanthus is a poorly known zoantharian genus in need of further study. Benthic surveys have shown that E. papillosus (until recently considered rare) is quite abundant in the Celtic Sea, Minches and northern North Sea, occurring as carcin-oecia formed in association with Anapagurus laevis (Anomura, Paguridae) and as smaller free-living colonies. It is also extensively distributed in the western Atlantic. A study of the cnidom in tentacles and mesenteric filaments has shown that carcinoecia contained fewer types and smaller numbers of nematocysts (basitrichs, p-mastigophores, and two different holotrich types) and spirocysts than free-living colonies, probably a consequence of being able to scavenge food from the pagurid. A method for obtaining quantitative estimates of spirocyst abundance is described. The mesenteric filaments of two of the three carcinoecia analysed contained numerous unexploded nematocysts (kleptocnidae) sequestered from the scyphomedusan Cyanea (probably C. capillata), presumably derived from the long tentacles trailing over the sea bed. This occurrence has never previously been recorded. The taxonomic study of larger, deep-sea, carcinoecium-forming species of Epizoanthus is complicated by the same paucity of nematocysts noted for E. papillosus.

Size-defined morphotypes in Zoanthus (Hexacorallia: Zoantharia) populations on shores in KwaZulu-Natal, South Africa.

Colonial zoanthids are a conspicuous feature of the subtropical rocky intertidal in KwaZulu-Natal but those of the genus Zoanthus have a confused taxonomy with 10, difficult to separate, nominal species described from the region. This paper presents an analysis of polyp size, measured as mean diameter determined photographically from the number of polyps occupying an area of 6 × 4 cm(2). The results, based on diameter frequency of 127 samples from five shores, indicate three populations (morphotypes) with means of 4.3 (SD ±0.53), 5.7 (SD ±0.70) and 8.4 (SD ±0.58) mm occurring in the approximate abundance ratios of 10:5:1, possibly corresponding to Zoanthus sansibaricus, Z. natalensis and Z. lawrencei. The underlying assumptions with regard to population structure (the number, size and degree of fragmentation of clones) and the normality of data are discussed, as are trans-oceanic larval dispersal, recruitment, and genetic connectivity. The essential, traditional species description in Zoanthus, using internal morphology, on its own may be an inadequate discriminator of species. The status of the few possibly valid species is discussed in relation to the present results and recent studies based on the application of molecular genetics. Thorough studies of the population structure (genets and ramets) and a taxonomic approach based on the combined use of morphology, genetic methods and statistically robust, quantitative morphometrics are proposed as a potential way forward.