0000000000049609
AUTHOR
ÁLvaro L. Peña Cantero
<strong>Review of some little-known benthic hydroids (Cnidaria, Hydrozoa) from the Southern Ocean</strong>
A number of benthic hydroid species inhabiting the Southern Ocean are insufficiently characterized. A revision of eight little-known Antarctic species of the order Anthoathecata was made, based on the study of type material. Some of the species have not been recorded since their original description a century ago. Four species (Bimeria corynopsis, Bougainvillia macloviana, ?Koellikerina belgicae and Rhizorhagium antarcticum) belong to the family Bougainvilliidae, two species (Hydractinia angusta and H. dendritica) to the family Hydractiniidae, Perarella clavata to the family Cytaeididae and, finally, Rhysia halecii to the family Rhysiidae. For each species a list of synonyms, a description,…
Species ofAntarctoscyphusPeña Cantero, García Carrascosa and Vervoort, 1997 (Cnidaria: Hydrozoa: Symplectoscyphidae) collected by US Antarctic expeditions: biogeographic implications
ABSTRACTAntarctoscyphus is one of the most characteristic genera of Antarctic benthic hydroids, with nine of the 10 known species considered to be endemic to the Antarctic; only Antarctoscyphus elongatus is also present in the sub-Antarctic region of Kerguelen. Accordingly, the genus was considered to have an Antarctic–Kerguelen distribution. Here we present the results of the study of the species of Antarctoscyphus collected from different Antarctic areas and from the Magellan region, during several expeditions under the United States Antarctic Research Program between 1958 and 1986. A scanning electron microscopy survey of all known species of the genus was carried out. Eight of the 10 kn…
Species of Acryptolaria Norman, 1875 (Cnidaria: Hydrozoa) collected by US Antarctic and sub-Antarctic expeditions.
Acryptolaria is a worldwide genus of deep-water benthic hydroids. The genus has relatively high species diversity, with 36 species described so far, yet most of them have been reported only occasionally. As a result, scientific knowledge of their ecology and distribution is scarce. Here I present the results of the study of species of Acryptolaria collected during several Antarctic and sub-Antarctic expeditions under the United States Antarctic Research Program between 1958 and 1986. Eight species were found in the collection (plus one determined to the genus level), with A. operculata having the highest occurrence. Acryptolaria flabellum is reported for the second time; the study also repr…
Inhabitant or visitor? Unexpected finding of Aglaophenia (Cnidaria, Hydrozoa) in Antarctic waters
AbstractBenthic hydrozoans are one of the most speciose and characteristic taxa from the Antarctic region, with a high number of endemic species, but diversity at the genus level is low and some families with world wide distribution are unrepresented. This is the case of the family Aglaopheniidae. A new species to science of the genus Aglaophenia Lamouroux has been found in the eastern end of the Weddell Sea, at depths of 65–116 m, within the material obtained by the German Antarctic expedition ANT XV/3. This finding constitutes a new record for the Weddell Sea fauna, the first evidence of the genus for the Polar Regions, and even the family Aglaopheniidae from Antarctic waters. The materia…
Areas of endemism in the Antarctic - a case study of the benthic hydrozoan genusOswaldella(Cnidaria, Kirchenpaueriidae)
Aim The aim of this study is to investigate areas of endemism within the distribution of Oswaldella species in the Southern Ocean, thereby testing previous hypotheses and proposing alternative scenarios for Antarctic evolution. Location Southern Ocean, Antarctic and sub-Antarctic waters of southern South America. Methods We prepared a database for the 31 currently known species of the Antarctic genus Oswaldella, which includes geographical locations gathered from published taxonomic studies as well as materials from museums and expeditions. A parsimony analysis of endemicity (PAE) was used to test hypotheses of distribution patterns. Results Four areas of endemism are hypothesized: southern…
Shallow-water benthic hydroids from the Maltese Islands (Central Mediterranean)
Forty species of benthic hydroids, belonging to 15 families and 21 genera, were found in a collection, obtained by SCUBA diving, from the Maltese Islands. Paradoxically for the well studied Mediterranean region, the hydroid fauna of these islands is virtually unexplored. Of 40 species, 33 were identified to species level, with 28 of them reported for the first time for the study area. Hydractinia monocarpa is recorded for the first time in the Mediterranean Sea, and a presumed new species of the genus Clytia has been found. The most speciose families are Campanulariidae with 10 species (25%), Aglaopheniidae with six species (15%) and Sertulariidae with five species (12%). Aglaophenia and Cl…
Additions to knowledge of the biodiversity of benthic hydroids (Cnidaria: Hydrozoa) in the Balleny Islands (Antarctica)
The Balleny Islands, an isolated archipelago located 240 km off the coast of Victoria Land (East Antarctica), are separated from the Antarctic continental shelf by waters more than 2000 m deep. The benthic hydroid fauna of these islands is little known, with only 25 species reported so far. The present study contributes to a better knowledge of the benthic hydrozoans inhabiting this archipelago by studying a small collection held at the National Institute of Water and Atmospheric Research Invertebrate Collection at Wellington, New Zealand. Sixteen species of benthic hydroids were found in the collection, belonging to nine families and 12 genera of Leptothecata. Kirchenpaueriidae and Oswalde…
Benthic hydroids (Cnidaria: Hydrozoa) from off George V Coast (East Antarctica)
Hydrozoans are one of the main and most characteristic zoological groups of Antarctic benthic communities, yet there are Antarctic areas where the hydrozoan fauna is completely unknown or scarcely known as off George V Coast (East Antarctica). Hitherto, only two studies have dealt with hydroids from this area and only 16 species have been reported. The present study contributes to increase knowledge of the benthic hydroid fauna off George V Coast by studying material collected during a sampling survey associated with the CEAMARC project. A total of 12 species of benthic hydroids were found. Anthoathecata is only represented by Bimeria corynopsis, the remaining species, including Schizotrich…
<p><strong>Revision of the Antarctic species of <em>Halecium</em> Oken, 1815 (Cnidaria, Hydrozoa, Haleciidae)</strong></p>
A revision of the known Antarctic species of the genus Halecium has been carried out, based on the study of both type and non-type material. For each species a list of synonyms, a diagnosis, a broad description (with the exception of the recently described H. frigidum and H. exaggeratum), a discussion of its relationship with other members of the genus, and an account of its autecological data are given. Thirteen Antarctic species of the genus, including H. pseudodelicatulum sp. nov. and H. pseudoincertus sp. nov., are considered valid. Halecium tubatum is considered as species inquirenda. Halecium ovatum and H. macrocaulus are considered to be junior synonyms of H. interpolatum and H. ince…
Towards a phylogenetic classification of Leptothecata (Cnidaria, Hydrozoa)
AbstractLeptothecata are hydrozoans whose hydranths are covered by perisarc and gonophores and whose medusae bear gonads on their radial canals. They develop complex polypoid colonies and exhibit considerable morphological variation among species with respect to growth, defensive structures and mode of development. For instance, several lineages within this order have lost the medusa stage. Depending on the author, traditional taxonomy in hydrozoans may be either polyp- or medusa-oriented. Therefore, the absence of the latter stage in some lineages may lead to very different classification schemes. Molecular data have proved useful in elucidating this taxonomic challenge. We analyzed a supe…
Breaking molds: Oswaldella laertesi, sp. nov., a unique Antarctic species of Oswaldella Stechow, 1919 (Cnidaria: Hydrozoa: Kirchenpaueriidae)
A new species of the Antarctic genus Oswaldella Stechow is described and figured, and its position amongst the remaining species of the genus is discussed. The material was collected from the Ross Sea area (Antarctica) during the BioRoss survey of the western Ross Sea and Balleny Islands in 2004. Oswaldella laertesi, sp. nov., is unique amongst known species of the genus in having hydrocladia arranged in three longitudinal rows.
Revision ofHalisiphoniaAllman, 1888 (Cnidaria, Hydrozoa, Hebellidae), with comments on its taxonomic position
The deep‐water genus Halisiphonia is reviewed, based on redescriptions of all available type specimens of its species. The genus includes four valid species, H. arctica, H. galatheae, H. megalotheca, and H. nana, and one species inquirenda, H. spongicola, for which the type could not be located.
An overview of the phylogeny of the families Lafoeidae and Hebellidae (Hydrozoa:Leptothecata): their composition and classification
A cladistic analysis of the genera of the family ‘Lafoeidae’ was performed in order to investigate suprageneric classifications and the boundaries of the family, as well as to organise the available morphological data and discuss the possible evolution of some morphological characters. Our results suggest that the former ‘Lafoeidae’ must be separated into two families: the Hebellidae and the Lafoeidae (including the subfamilies Lafoeinae and Zygophylacinae).
Polar marine biology science in Portugal and Spain: Recent advances and future perspectives
Xavier, José C. et al.
Revision of the genus Filellum Hincks, 1868 (Lafoeidae, Leptothecata, Hydrozoa)
A taxonomic review of the cosmopolitan genus Filellum was performed considering morphology, morphometry and cnidome. Species for which we had access to materials were redescribed and morphologically characterized based on optical and scanning electron microscopy (SEM). The materials examined belong to museum collections, including type specimens. All records found in the literature were checked. Our analyses confirmed the validity of 10 out of the 18 nominal species referred to the genus, and established four others (F. adnatum, F. bouvieri, F. contortum and F. plicatum) as species inquirenda. A new species, Filellum bouvetensis sp. nov., is described. The species Reticularia annulata Watso…
Benthic hydroids from off Low Island (Southern Ocean, Antarctica)
A survey of marine benthic community biodiversity off Low Island (Southern Ocean) was carried out by the Spanish Antarctic Expedition Bentart 2006, using the BIO Hesperides. Samples from the expedition included an important collection of hydroids. A total of 39 species was recorded, two of them being new to science (Eudendrium bentart sp. nov., and Orthopyxis curiosa sp. nov.), belonging to the subclasses Anthoathecata and Leptothecata. Anthoathecates are represented by only two species, both referable to the genus Eudendrium. The 37 leptothecate species belong to the families Campanulinidae, Lafoeidae, Haleciidae, Schizotrichidae, Kirchenpaueriidae, Sertulariidae and Campanulariidae. Sertu…
Phylogenetic analysis of the Antarctic genus Oswaldella Stechow, 1919 (Hydrozoa, Leptomedusae, Kirchenpaueriidae)
A cladistic study was carried out on known species of the characteristically Antarctic genus Oswaldella, adopting as out-groups some other genera included in the family Kirchenpaueriidae. The analysis resulted in a cladogram with low CI in which no relationship between genera can be depicted. However, the hypothesis of monophyly of the genus Oswaldella is corroborated, being supported in our cladogram by five synapomorphies (although all are homoplastic with other taxa or reversed within the species of the genus). The basal relationships of the genus are uncertain, but three species groups are distinguishable within Oswaldella: 1) the O. incognita group, 2) the O. Antarctica group, and 3) a…
Species ofAcryptolariaNorman, 1875 (Cnidaria, Hydrozoa, Lafoeidae) collected in the Western Pacific by various French expeditions, with the description of nineteen new species
Pena Cantero A. L. & Vervoort W. 2010. — Species of Acryptolaria Norman, 1875 (Cnidaria, Hydrozoa, Lafoeidae) collected in the Western Pacific by various French expeditions, with the description of nineteen new species. Zoosystema 32 (2): 267-332.
Revision of the genusAcryptolariaNorman, 1875 (Cnidaria, Hydrozoa, Lafoeidae)
The genus Acryptolaria is reviewed, with a complete redescription of the type specimens, with the exception of A. andersoni and A. rectangularis for which type material could not be located. The genus includes 16 valid species, though A. andersoni is insufficiently known. All records found in the literature have been checked. The cnidome proved to be a useful tool for species identification. A key for the identification of the species of the genus is also presented.
On six new species of Zygophylax Quelch, 1885 (Cnidaria, Hydrozoa, Zygophylacidae) from the New Calendonian region.
Six new species of Zygophylax (Z. dispersa sp. nov., Z. encarnae sp. nov., Z. laertesi sp. nov., Z. medeae sp. nov., Z. niobae sp. nov. and Z. pseudoabietinella sp. nov.) are described and figured. The material studied was present in collections from several French expeditions in the western Pacific, mostly in the waters around New Caledonia and vicinity.
Redescription and systematic status of the Antarctic genusAbietinellaLevinsen, 1913 (Lafoeidae, Hydrozoa, Cnidaria)
The Antarctic–Patagonian genus Abietinella, comprising two known species, Abietinella operculata (Jaderholm, 1903) and Abietinella grandis (Vanhoffen, 1910), is reviewed. The holotype of Abietinella operculata is fully redescribed, including morphometry and cnidome, unknown up to now. Its distinctive characters are the growth habit, hydrothecal shape and, most important, the presence of a dish‐shaped operculum attached to the adcauline side of the hydrothecal aperture. We corroborate its conspecificity with A. grandis and, therefore, the monotypic condition of Abietinella.
Revision of the genusCryptolarellaStechow, 1913 (Lafoeidae, Leptothecata, Hydrozoa)
The bathyal genus Cryptolarella, comprising three known species, Cryptolarella abyssicola (Allman, 1888), Cryptolarella diffusa (Allman, 1888) and Cryptolarella humilis (Allman, 1888), is reviewed after the study of the holotypes of the species. A complete redescription and characterization of the species, including new data concerning morphometry and cnidome is presented, and its literature data reviewed. We conclude that all species are conspecific, resulting in a single valid species, C. abyssicola. The distinctive characters of the species are the growth habit, gonothecal arrangement and cnidome.
Benthic hydroids (Cnidaria, Hydrozoa) from the Ross Sea (Antarctica) collected by the New Zealand Antarctic expedition BioRoss 2004 with RV Tangaroa
During the New Zealand BioRoss 2004 survey, with RV Tangaroa , sampling of marine communities on the Ross Sea shelf was undertaken. Samples were obtained employing several sampling gears (Van Veen grab, epibenthic sled, rough bottom trawl, and beam trawl). Among the numerous benthic samples obtained, a large and important collection of hydroids was present. Sixty-one species, four of them new to science ( Monocoryne antarctica sp. nov., Halecium tangaroa sp. nov., Staurotheca gracilis sp. nov. and Symplectoscyphus densus sp. nov.) have been recorded. Oswaldella blanconae sp. nov. is also described. “Anthoathecata” are represented by ten species belonging to the families Bougainvilliidae, Ca…
Southern Ocean areas of endemism: a reanalysis using benthic hydroids (Cnidaria, Hydrozoa)
The biogeographic history of the Southern Ocean (SO) fauna is complex and poorly studied, especially the areas of endemism. We reanalyzed the data of Marques & Peña Cantero (2010), along with other geographical records of endemic benthic hydroids below 45°S. A Parsimony Analysis of Endemicity (PAE) based on 5° latitude by 5° longitude matrix with 61 species resulted in eight areas of endemism. We discuss these results in the context of different hypotheses of the evolution of the SO fauna and previously proposed biogeography patterns.
Benthic hydroids (Cnidaria, Hydrozoa) from the Weddell Sea (Antarctica)
Hydrozoans are a conspicuous component of Antarctic benthic communitites. Recent taxonomic effort has led to a substantial increase in knowledge on the diversity of benthic hydroids from some areas of the Southern Ocean, including the Weddell Sea, the largest sea in the Antarctic region. However, the study of many hydrozoan taxa are still pending, and the diversity in this huge region is expected to be higher than currently known. In order to contribute to the knowledge of taxonomy, ecology and distribution of these cnidarians, a study of unpublished material collected by several German Antarctic expeditions aboard the RV Polarstern in the eastern sector of the Weddell Sea has been conducte…