RESUMO
The present paper reports on 22 bryozoan species collected from 25 localities on the Southwestern Atlantic continental shelf and slope by the Instituto Español de Oceanografía vessel RV Miguel Oliver (2008-2010). Two new genera, Amynaskolia n. gen. and Biconcavus n. gen., and twenty new cheilostome species are described: Amastigia zigzag n. sp., Membranicellaria balanyai n. sp., Figularia dimorpha n. sp., Biconcavus batmani n. sp., Smittina acicularis n. sp., Smittoidea granulosa n. sp., Amynaskolia foramina n. sp., Mawatarius avilae n. sp., Mucropetraliella reticulata n. sp., Ipsibuffonella umbonata n. sp., Microporella gappai n. sp., Fenestrulina curviscutum n. sp., Fenestrulina multiflorum n. sp., Malakosaria cecilioi n. sp., Osthimosia incisa n. sp., Spigaleos simplex n. sp., Reteporella kuklinskii n. sp., Reteporella maryae n. sp., Reteporella taylori n. sp., Orthoporidra nova n. sp.. New taxonomic remarks are also included for two little-known species: Melicerita atlantica Busk, 1884 and Arachnopusia tubula Hayward Thorpe, 1988. Membranicellaria balanyai n. sp., Mawatarius avilae n. sp. and Ipsibuffonella umbonata n. sp. represent the third described species of their genera, whereas Spigaleos simplex n. sp., Malakosaria cecilioi n. sp. and Orthoporidra nova n. sp. are the fourth, fifth and sixth described species of their genera respectively. Spigaleos (Celleporidae) and Arachnopusia tubula (Arachnopusiidae), previously reported only from Antarctica, Ipsibuffonella (Buffonellodidae), reported from tropical and subtropical regions, and Mucropetraliella (Petraliidae) all represent first records for the Patagonian region, expanding their geographic distributions northwards and southwards, respectively. These results highlight the importance of sampling the slope and deep waters of South American and Antarctic margins and basins, filling significant gaps in the knowledge of the biodiversity and biogeographic ranges of certain taxa in these unique and varied ecosystems.
Assuntos
Briozoários , Animais , Regiões Antárticas , Biodiversidade , EcossistemaRESUMO
Bryozoans constitute an important component of marine-fouling communities of anthropogenic substrata. Many species have been reported as exotic or widespread around the world, typically in ports and harbors of non-polar regions. Here we present the first record of a species of the bryozoan Triphyllozoon in the Atlantic Ocean. Triphyllozoon arcuatum (MacGillivray, 1889), described originally from Australia, is reported herein from natural substrata in Singapore and natural and artificial substrata in Brazil. Although easily recognizable, the species has not been previously reported from anywhere else in the Atlantic. In the latter instance, the species was collected during monitoring of the invasive scleractinian corals Tubastraea spp. on an oil platform originally from Singapore and now located at Todos os Santos Bay, northeastern Brazil. Colonies of T. arcuatum were also found associated with three species of sponges, giving evidence that it is also growing in the natural environment. Todos os Santos Bay is characterized by intense commercial shipping traffic and oil exploration and the finding of T. arcuatum on an oil platform provides strong evidence that it represents a non-indigenous species in the Atlantic. Owing to the possible impact of T. arcuatum in Brazil, further studies and monitoring of its bioinvasion are recommended.(AU)
Assuntos
Animais , Briozoários/anatomia & histologia , Biodiversidade , Oceano AtlânticoRESUMO
Bryozoans constitute an important component of marine-fouling communities of anthropogenic substrata. Many species have been reported as exotic or widespread around the world, typically in ports and harbors of non-polar regions. Here we present the first record of a species of the bryozoan Triphyllozoon in the Atlantic Ocean. Triphyllozoon arcuatum (MacGillivray, 1889), described originally from Australia, is reported herein from natural substrata in Singapore and natural and artificial substrata in Brazil. Although easily recognizable, the species has not been previously reported from anywhere else in the Atlantic. In the latter instance, the species was collected during monitoring of the invasive scleractinian corals Tubastraea spp. on an oil platform originally from Singapore and now located at Todos os Santos Bay, northeastern Brazil. Colonies of T. arcuatum were also found associated with three species of sponges, giving evidence that it is also growing in the natural environment. Todos os Santos Bay is characterized by intense commercial shipping traffic and oil exploration and the finding of T. arcuatum on an oil platform provides strong evidence that it represents a non-indigenous species in the Atlantic. Owing to the possible impact of T. arcuatum in Brazil, further studies and monitoring of its bioinvasion are recommended.
Assuntos
Animais , Biodiversidade , Briozoários/anatomia & histologia , Oceano AtlânticoRESUMO
Members of the bryozoan family Hippoporidridae have frequently been found encrusting gastropod shells inhabited by hermit crabs, with which they appear to enter into a symbiotic relationship-shells occupied by hermits may in some species have a tubular extension of the encrusting bryozoan from the shell opening, induced by the presence of the crab. Such colony growth is characteristic of some species of Hippoporidra Canu and Bassler and Odontoporella Héjjas. The type species of Odontoporella, O. adpressa (Busk), has been attributed a nominal distribution from Chiloe Island, Chile (the type locality), to the Falkland Islands, New Zealand, and New Caledonia. In New Zealand, colonies are relatively easily obtainable from some localities, so a study was undertaken to ascertain substratum and morphometric relationships across the range of distribution of the species, using museum specimens and, where possible, fresh material. It became clear that the New Zealand population constitutes a separate species, here named O. bishopi n. sp., in which the orifice is proportionately larger than in O. adpressa. In contrast to O. adpressa, which settles on a range of substrata, O. bishopi preferentially settles on gastropod shells occupied by hermit crabs (mostly Paguristes setosus (H. Milne Edwards)) and shows sexual dimorphism at the level of the polypide. Male polypides not only have modified lophophores but also reduced guts.