RESUMO
Bryozoans are a key group of sessile invertebrates in some reef frameworks but are typically neglected in environmental monitoring programs. Abrolhos Bank (Brazil) is the largest reef complex in the South Atlantic Ocean, encompassing several reef landscapes over an area of 46,000 km2. A transition takes place across the shelf from mangroves to soft sediments, coastal shallow reefs to a volcanic archipelago - surrounded by fringing reefs - and unique mushroom-shaped biogenic structures, with mesophotic pinnacle reefs, rhodolith beds, sink-holes and shelf break deep environments. The taxonomic composition of the bryozoan fauna was studied in 11 core samples taken from shallow to mesophotic mid-shelf reefs (4-25 m deep) on Abrolhos Bank by divers using a submersible drill. Of the 20 bryozoan species sampled, 17 are new records for Abrolhos Bank and seven species are new to science: Crassimarginatella winstonae n. sp., Parasmittina distincta n. sp., Parasmittina abrolhosensis n. sp., Hemismittoidea asymmetrica n. sp., Stylopoma variabilis n. sp., Stylopoma hastata n. sp., and Plesiocleidochasma acuminata n. sp. (described by Ramalho, Taylor Moraes). The most conspicuous species is Celleporaria atlantica. These results increase to 48 the total number of bryozoan species known in this region and reinforce the importance of this group as one of the main components apart from crustose coralline algae and corals of the reef framework-building community of Abrolhos Bank.
Assuntos
Recifes de Corais , Ecologia , Animais , Antozoários , Oceano Atlântico , BrasilRESUMO
As sessile organisms, bryozoans are among the commonest components of the encrusting communities on hard substrata. On unconsolidated bottoms, benthic animals and their carapaces, including mollusk shells, represent potential surfaces for encrustation. Here we describe the bryozoan fauna growing on disarticulated bivalve shells collected intertidally on Itaparica beach, Todos os Santos Bay, northeast Brazil. We examined a total of 382 valves representing seven species of bivalves, among which we found 82 valves of three bivalve species to be encrusted by bryozoans, with 109 bryozoan colonies detected overall. We identified 11 cheilostome bryozoan species, among which Phidoloporidae and Smittinidae were the most diverse, with four and two species, respectively. We redescribed two bryozoan species, Parasmittina loxoides and Rhynchozoon phrynoglossum, and describe another two, Pleurocodonellina marcusi n. sp. and Rhynchozoon itaparicaensis n. sp., as new. A new combination for Cribella triangulata Canu Bassler, 1928 is proposed, including Calyptotheca tenuata Harmer, 1957 as a new junior subjective synonym of Calyptotheca triangulata n. comb. All but one of the 11 species have encrusting colonies; Licornia aff. diadema, forms erect branching colonies. For seven of the bryozoans, ours are the first records of these species growing on shells. Although the majority of bryozoans we studied have also been reported on other substrata, Rhynchozoon brasiliensis and Parasmittina loxoides were predominant in the fauna, comprising 79 (72%) of all colonies inventoried. Due to the lack of information on the distribution of these species in northeastern Brazil, further studies are needed to determine whether they show any substratum preference.
Assuntos
Briozoários , Animais , Baías , Bivalves , BrasilRESUMO
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
Eutaleola nom. nov. is proposed as a replacement name for Euteleia Marcus, 1938 (Bryozoa: Cheilostomata), a secondary homonym of Euteleia Raffray, 1904 (Arthropoda: Coleoptera). Eutaleola is a monospecific genus of Pasytheida e, found in warm shallow waters on both sides of the Atlantic and in deeper waters of the eastern Pacific. Brazilian material of Eutaleola evelinae (Marcus, 1938) comb. nov. is described and illustrated.
RESUMO
Eutaleola nom. nov. is proposed as a replacement name for Euteleia Marcus, 1938 (Bryozoa: Cheilostomata), a secondary homonym of Euteleia Raffray, 1904 (Arthropoda: Coleoptera). Eutaleola is a monospecific genus of Pasytheida e, found in warm shallow waters on both sides of the Atlantic and in deeper waters of the eastern Pacific. Brazilian material of Eutaleola evelinae (Marcus, 1938) comb. nov. is described and illustrated.
RESUMO
Eutaleola nom. nov. is proposed as a replacement name for Euteleia Marcus, 1938 (Bryozoa: Cheilostomata), a secondary homonym of Euteleia Raffray, 1904 (Arthropoda: Coleoptera). Eutaleola is a monospecific genus of Pasytheida e, found in warm shallow waters on both sides of the Atlantic and in deeper waters of the eastern Pacific. Brazilian material of Eutaleola evelinae (Marcus, 1938) comb. nov. is described and illustrated.