Dale R. Calder

Additions to the hydroids (Cnidaria) of the Galápagos, with a list of species reported from the islands

The hydroid fauna of the Galápagos Islands, Ecuador, is known largely from reports of collections made between 1932 and 1938 during several Allan Hancock Pacific Expeditions. Of some 100 nominal species (excluding Stylasteridae) reported from the archipelago overall, including species obtained during other expeditions, 81 are recognized as valid. An additional 15 species are added here, 14 of them based on collections undertaken between 1992 and 2000. Leptothecates account for 66 of the 96 species, while anthoathecates comprise the remaining 30. One previously undescribed leptothecate, Halopteris violae, sp. nov., is characterized and compared with H. tenella (Verrill, 1874) and H. minuta (Trebilcock, 1928), species it closely resembles. Gonothecae of Sertularella costata Leloup, 1940 are described for the first time. Plumularia galapagensis, nom. nov., is proposed as a replacement name for the invalid junior primary homonym Plumularia tenuissima Fraser, 1938b (not Plumularia tenuissima Totton, 1930). Under provisions of the International Code of Zoological Nomenclature, the widely used name Cladocoryne floccosa Rotch, 1871 is designated a nomen protectum and assigned precedence over its largely unknown senior synonym Hydra corynaria Bosc, 1797, which is reduced to the status of nomen oblitum. Balella irregularis (Fraser, 1938) from the Galápagos is considered conspecific with Balella mirabilis (Nutting, 1905) from Hawaii and Japan. Six new combinations are introduced: Bimeria laxa Fraser, 1938a is assigned to the genus Garveia Wright, 1859, as G. laxa (Fraser, 1938a); Tubularia integra Fraser, 1938a is assigned to Ectopleura L. Agassiz, 1862, as E. integra (Fraser, 1938a); Campanulina ramosa Fraser, 1938a is assigned to Opercularella Hincks, 1868, as O. ramosa (Fraser, 1938a); Bonneviella minor Fraser, 1938a is assigned to Scandia Fraser, 1912, as S. minor (Fraser, 1938a); Campanularia gracilicaulis Fraser, 1938a is assigned to Clytia Lamouroux, 1812, as C. gracilicaulis (Fraser, 1938a); Sertularia anceps Fraser, 1938a is assigned to Dynamena Lamouroux, 1812, as D. anceps (Fraser, 1938a). Hydroids of the Galápagos are moderately well known faunistically, at least in comparison with those of other areas in the Eastern Pacific Tropical Region.

Reproduction, planula development, and substratum selection in three species of Stylactaria (Cnidaria: Hydrozoa) from Hokkaido, Japan

Modes of reproduction, morphology and behaviour of planulae, and substratum specificity were studied and compared in three species of the hydrozoan genus Stylactaria from Hokkaido, S. conchicola, S. uchidai, and S. multigranosi. Observed differences in these attributes provide additional characters for discrimination of the three species. Stylactaria conchicola is oviparous, its planulae are sedentary, and its hydroid is substratum specific (living only on shells of the gastropod Homalopoma amussitatum). Stylactaria uchidai differs in being ovoviviparous, in having crawling planulae, and in being a substratum generalist. Stylactaria multigranosi is parthenogenetic, its planulae are sedentary, and it is substratum specific (occurring exclusively on the gastropod Nassarius multigranosus). Only female colonies of S. multigranosi are known, and gonophores of this species differ from those of S. conchicola and S. uchidai in being eumedusoid rather than styloid. Correlations were noted between attributes of the...

Hydroids from Rocas Alijos

Knowledge of the hydroids of the tropical and subtropical northeast Pacific Ocean is based almost entirely on extensive collections made by the Allan Hancock Pacific Expeditions between 1932 and 1938, and studied by Fraser (1938a,b,c, 1939, 1948). Those collections, undertaken during cruises of the Velero III, included hydroids from coastal areas between Peru and the west coast of the United States, as well as from the Galapagos Islands, the Islas Revillagigedo, and other oceanic islands of the region. Excluding the fauna from temperate waters off Peru and the United States west coast, a diverse assemblage comprising nearly 300 species of hydroids was reported by Fraser from the region. Of these, 107 species were identified from the oceanic islands offshore (Fraser, 1948).

Similiclava nivea (Cnidaria: Hydrozoa: Similiclavidae): a new family, genus and species of athecate hydroid from the Pacific coast of North America

The hydroid Similiclava nivea, gen. nov., sp. nov., is described from colonies collected in nearshore waters of southern British Columbia, Canada. It has been observed by divers, and recorded as Clava sp., several hundred times at locations between southeast Alaska and southern Oregon, USA. While resembling the hydractiniid Clava multicornis, tentacles of S. nivea are arranged in two close whorls in extended hydranths rather than being scattered over the distal end of the hydranth. Moreover, the hypostome is dome-shaped to flattened instead of being proboscidiform. Similiclava nivea also resembles species of the hydractiniid genera Stylactaria, Hydractinia and Podocoryna, but differs in being monomorphic, in lacking spines on the hydrorhiza and in having numerous (as many as 50 or more) sporosacs borne in a broad whorl below the tentacles on normal hydranths. Molecular analysis using the mitochondrial 16S gene sequences reveals that S. nivea is closer to Clathrozoellidae than to Hydractiniidae, although it is clearly distinct from both. A new family, Similiclavidae, is established to accommodate the species. Hydroids of S. nivea were observed at relatively shallow depths (10–30 m) on rocks and epibiota attached to rocky substrates. Colonies are conspicuous because of the relatively large surface area they occupy (up to 20 cm across, and in aggregations often exceeding 100 or more hydranths) together with the height (about 15 mm high when extended) and striking white colour of living hydranths. The cnidome consists of desmonemes, microbasic euryteles and microbasic mastigophores. A substrate generalist observed on rocks, algae, sponges, barnacles, bryozoans and other hydroids in cold-temperate waters, S. nivea is most prevalent in shallow subtidal areas swept by tidal currents. http://zoobank.org/urn:lsid:zoobank.org:pub:2691E02E-7E14-4820-8D91-41D9E7E8BF62

Aglaopheniid hydroids (Cnidaria: Hydrozoa: Aglaopheniidae) from bathyal waters of the Flemish Cap, Flemish Pass, and Grand Banks of Newfoundland (NW Atlantic) .

Five species of aglaopheniid hydroids (Aglaophenopsis cornuta, Cladocarpus diana, C. formosus, C. integer, and Nematocarpus ramuliferus) were collected from the Flemish Cap, Flemish Pass, and Grand Banks of Newfoundland during surveys with bottom trawls, rock dredges, and scallop gear. All are infrequently reported species, with C. diana being discovered for the first time since its original description from Iceland. We document here the southernmost collections of C. diana and N. ramuliferus, both previously unknown in the western Atlantic. Each of the five species is described and illustrated based on fertile material, a key is provided for their identification, and bathymetric distributions are noted. Known depth ranges are extended for A. cornuta, C. diana, and C. integer. Aglaophenopsis and Nematocarpus are recognized as genera distinct from the polyphyletic Cladocarpus, based on the unique structure of the phylactocarp in the former, and the existence of appendages with nematothecae (ramuli) on almost all thecate internodes of hydrocladia in the latter. These appendages occur even in the absence of gonothecae, and are here considered defensive structures that protect the hydranths. In differing from typical phylactocarps, we accept the contention that they are characters of generic value.

Names of hydroids (Cnidaria, Hydrozoa) established by Charles McLean Fraser (1872–1946), excluding those from Allan Hancock Expeditions

An account is given of the names of families, genera, and species of hydroids established by C.M. Fraser of Canada, excluding those from Allan Hancock Pacific Expeditions and the Allan Hancock Caribbean Sea Expedition. The names of four families, 11 genera, and 101 species are attributed to him in this work, complementing those of another two genera and 164 species described by Fraser in various Allan Hancock publications. Information is provided on type localities of his new species, on locations and kinds of type material in existence, where known, and on the current taxonomic status of families, genera, and species described by him in works reviewed herein. Two replacement names (Thuiaria geniculata Fraser, 1918a and Salacia fraseri Calder, 1991) exist for Thuiaria distans Fraser, 1914a (not Thuiaria distans Allman, 1877). The widely overlooked senior synonym, T. geniculata, is recognized as the valid name of the species. Diphasia alta nom. nov. is proposed as a new replacement name for the permanently invalid junior primary homonym Diphasia robusta Fraser, 1943a (not D. attenuata robusta Billard, 1924). In addition, Cryptolaria crassa nom. nov. is proposed as a new replacement name for the junior secondary homonym Cryptolaria rigida (Fraser, 1948) [not C. rigida (Fraser, 1940a)]. Lectotypes have been designated for 47 of the species to establish objective standards for application of their names. Corymorpha adventitia Fraser, 1941b, from the Pacific coast of Panama, is assigned to Ralpharia Watson, 1980, as R. adventitia. No type specimens are known to exist for seven of the species considered, including one holotype (of Hebella eximia Fraser, 1944a) missing from its bottle. Particular attention has been paid to dating and chronology of the 51 publications of Fraser covered in this work. Earlier bibliographic errors are corrected, most notably establishing that the book Distribution and relationship in American hydroids was published in early 1947 rather than 1946 as per the title page.

One new genus and three new species of plumulariid hydroids (Cnidaria, Hydrozoa, Plumulariidae) from the western Pacific Ocean, with a re-examination of Plumularia insignis Allman, 1883 and related taxa

One new genus (Schizoplumularia) and three new species (Schizoplumularia vervoorti, S. geniculata and S. elegans) of plumulariids are recognized and described from large collections of plumularioid hydroids collected in New Caledonia and vicinity during several French expeditions. During taxonomic studies of these hydroids, colonies were compared with type material of Plumularia insignis Allman, 1883 and several other similar species-group taxa. As a result, three of the latter (P. flabellum Allman, 1883, P. conjuncta Billard, 1913, and P. billardi nom. nov.) are recognized as valid in addition to P. insignis. The binomen P. billardi is a replacement name for P. insignis var. gracilis Billard, 1913. In being elevated to the rank of species in this work, it becomes an invalid junior primary homonym of several others having the same name.

Margelopsis gibbesii (McCrady, 1859) (Cnidaria, Hydrozoa): taxonomic review, and conservation of usage by designation of a lectotype

The binomen Nemopsis gibbesii McCrady, 1859, originally applied to a species of hydromedusa and its supposed hydroid from South Carolina, USA, has been known for more than a century to encompass two species. The medusa stage is conspecific with that of Nemopsis bachei L. Agassiz, 1849, while the hydroid stage is referable to the genus Margelopsis Hartlaub, 1897. Both that hydroid, and the medusa stage now subjectively linked to it, are commonly assigned to M. gibbesii. With no type having ever been designated for McCradys species, a lectotype is designated to stabilize nomenclature of the species and serve as the standard for application of the name. In the absence of type specimens, an illustration of the hydroid of N. gibbesii by McCrady is chosen as lectotype, thereby conserving the name Margelopsis gibbesii in its accustomed usage. Hydroids and medusae of the species are re-described from new material, the cnidome of both stages is characterized, and a taxonomic review is given. The hydroid stage is reported for the first time since its original description in the mid-19th century. Medusae of M. gibbesii are also seen infrequently, having been reported only six times earlier.