Edmundo Ferraz Nonato

Benthic megafauna of the nearshore zone of Martel Inlet (King George Island, South Shetland Islands, Antarctica): depth zonation and underwater observations

Abstract The benthic megafauna from the soft bottoms of the shallow coastal zone of Martel Inlet (Admiralty Bay, King George Island, South Shetland Islands, Antarctica) was studied during three austral summers (1989/1990, 1990/1991 and 1994/1995) in relation to the bathymetric features. Surveying and sampling, based on specimen counting and underwater observations, were undertaken by scuba-diving at depths down to 25 m. The depth zonation appears to be influenced by the nature of the substrate and especially by the action of the ice. The multiple action of ice flows prevents the occurrence of sessile forms in the shallower areas, where a low-diversity community, dominated by motile animals, was found. In the area around 18 m in depth, the action of icebergs generated faunistic and sedimentary patches of impacted and non-impacted areas. The more stable conditions prevailing below depths of 20–25 m allowed the establishment of a more diversified epifauna, including many sessile forms. The interannual differences observed in the densities of the mobile isopod Serolis polita may be associated with the summer period when the sampling was undertaken.

Biotic interaction between spionid polychaetes and bouchardiid brachiopods: Paleoecological, taphonomic and evolutionary implications

Shells of Bouchardia rosea (Brachiopoda, Rhynchonelliformea) are abundant in Late Holocene death assemblages of the Ubatuba Bight, Brazil, SW Atlantic. This genus is also known from multiple localities in the Cenozoic fossil record of South America. A total of 1211 valves of B. rosea, 2086 shells of sympatric bivalve mollusks (14 nearshore localities ranging in depth from 0 to 30 m), 80 shells of Bouchardia zitteli, San Julián Formation, Paleogene, Argentina, and 135 shells of Bouchardia transplatina, Camacho Formation, Neogene, Uruguay were examined for bioerosion traces. All examined bouchardiid shells represent shallow-water, subtropical marine settings. Out of 1211 brachiopod shells of B. rosea, 1201 represent dead individuals. A total of 149 dead specimens displayed polychaete traces (Caulostrepsis). Live polychaetes were found inside Caulostrepsis borings in 10 life-collected brachiopods, indicating a syn-vivo interaction (Caulostrepsis traces in dead shells of B. rosea were always empty). The long and coiled peristomial palps, large chaetae on both sides of the 5th segment, and flanged pygidium found in the polychaetes are characteristic of the polychaete genus Polydora (Spionidae). The fact that 100% of the Caulostrepsis found in living brachiopods were still inhabited by the trace-making spionids, whereas none was found in dead hosts, implies active biotic interaction between the two living organisms rather than colonization of dead brachiopod shells. The absence of blisters, the lack of valve/site stereotypy, and the fact that tubes open only externally are all suggestive of a commensal relationship. These data document a new host group (bouchardiid rhynchonelliform brachiopods) with which spionids can interact (interestingly, spionid-infested sympatric bivalves have not been found in the study area despite extensive sampling). The syn-vivo interaction indicates that substantial bioerosion may occur when the host is alive. Thus, the presence of such bioerosion traces on fossil shells need not imply a prolonged post-mortem exposure of shells on the sea floor. Also, none of the Paleogene and Neogene Bouchardia species included any ichnological evidence for spionid infestation. This indicates that the Spionidae/ Bouchardia association may be geologically young, although the lack of older records may also reflect limited sampling and/or taphonomic biases.

Anelídeos poliquetas do nordeste do Brasil: I - poliquetas bentônicos da costa de Alagoas e Sergipe

Num trabalho anterior (NONATO & LUNA, 1969) discutimos as especies de poliquetas de escama que fazem parte de uma colecao proveniente de dragagens executadas pelo Laboratorio de Ciencias do Mar da Universidade Federal de Pernambuco, no Nordeste do Brasil. No atual, sao tratadas as especies desprovidas de escamas, em numero de 71. Informacoes sobre a area amostrada estao contidas nos trabalhos de CAVALCANTI & colab. e de MABESOONE & TINOCO, 1967. Especies pequenas e delicadas que constituem parte ponderavel das populacoes bentonicas foram muito raras nesta area. Isto pode ser devido a condicoes eventualmente adversas ou, muito mais provavelmente, e consequencia de sua destruicao durante a coleta e triagem. Os fundos duros predominantes, com superficie irregular e constituidos em grande parte por blocos ou cascalho de algas calcarias e corais, tornam particularmente ardua a amostragem biologica. Nessas condicoes e dificil preservar a integridade de seres de corpo delicado como os poliquetas, da acao trituradora, dentro dos aparelhos de coleta. Devemos ter em conta essa circunstância ao avaliar a densidade aparente da fauna. Os poliquetas nao devem ser tao pouco frequentes como indica o resultado da prospeccao atual. Acreditamos que o uso de melhores tecnicas permitira apreciar a sua verdadeira densidade e conhecer melhor sua distribuicao. A pesca noturna, com luz submersa, por exemplo, podera ser um excelente metodo para atrair especies do substrato ou de habitats de outra forma inaccessiveis. Das 71 especies, apenas uma foi considerada como nova para a ciencia. Scoloplis agrestis sp. nov. assemelha-se a S. robustus Rullier e a S. madagascarensis Fauvel, diferindo de ambas pelo numero de setigeros toracicos e pelo numero reduzido de cerdas aciculares dos neuropodios toracicos. Os Eunicea sao o grupo melhor representado, com 26 especies, das quais a mais comum e Eunice longicirrata Webster (108 exemplares em 19 estacoes). Diopatra spiribranchis Augener e Hypsicomus elegans Webster sao consideradas boas especies. Somente dois Flabelligerideos foram capturados em toda a area; um deles e um especimem bem conservado de Pherusa scutigera (Ehlers) e o outro um Piromis sp. A maior parte das especies desta colecao e constituida por formas semelhantes as encontradas na regiao das Antilhas, como, alias, seria de se esperar. Porem, algumas aproximam-se de especies do Pacifico e do Indico, como e o caso de Glycera longipinnis Grube, Onuphis litoralis Monro e Vermiliopsis acanthophora Augener, cujas caracteristicas concordam perfeitamente com as descricoes a que tivemos acesso.

Bathymetric distribution of the meiofaunal polychaetes in the nearshore zone of Martel Inlet, King George Island, Antarctica

Polychaetes, the dominant macrofaunal taxa of the Antarctic soft sediments, provided more than 40% of the animals found in Martel Inlet. However, little information is available on the composition of meiofaunal communities in polar areas. This study identified the meiofaunal polychaete species and described their bathymetric distribution in the nearshore zone. Sediment cores were taken by divers from 6–25 m depth in the summer of 1991 and 1994 in front of the Brazilian Antarctic Station (Martel Inlet, Admiralty Bay). Additional sampling was done at the 18 m depth in 1994 in order to study the influence of ice scouring. A total of 1895 specimens in 17 families were found. Three species (Apistobranchus glacierae, Leitoscoloplos kerguelensis and Ophryotrocha notialis), all of them belonging to the temporary meiofauna, provided more than 70% of the total polychaete fraction. This meiofaunal component showed similar distributional patterns to those of the macrofaunal polychaetes in this area.

Trophic relationships between polychaetes and brachyuran crabs on the southeastern Brazilian coast

Polychacte annelids constitute an important fecding resouree for several spccics of the benthic and dcmersal marine fauna. Their role in the energetic flow of marine ecosystems has been made evidenced by thcir contribution to the diet of fishes (Amaral & Migotto, 1980;Ben-Elihau et 01.,1983;Ben-Elihau & Golani, 1990;Amaral et al., 1994) and crabs (Schembri, 1981; Le Calvez, 1984; 1987;HalI et ai., 1990). The main difficultywhcn studying the diet of crabs is the identification of stomach contents to specific leveI. Nevertheless, concerning the polychaetes, the presence of certain structures which are more resistant to digestion, such as setae, uncini, hooks, mouthpieces and opercula, allowsthe determination to familyleveI.The analysis at this leveI is justified by the great within-family homogeneity regarding the trophic group, position in the sediment and feeding strategies, alI of whichare in agreement with the conccpt of fceding guilds by Fauchald & Jumars (1979). The feeding guild approach has been demonstrated to be rather useful in trophic ecology studies (Maurer & Leathem, 1981;Bianchi & Morri, 1985;Paiva, 1993). Considering that brachyuran crabs are the main megabenthic group (Sartor, 1989; Pires, 1992) and polychaetes the main macrobenthic group in the studied arca (Paiva, 1990; PiresVanin, 1993), the knowledge of their interrelations are fundamental in arder to understand the local trophic web.

Contribuição ao conhecimento da fauna de peixes do litoral norte do Estado de São Paulo

Na execucao de um programa de levantamento das faunas demersal e epibentonica da plataforma do litoral norte do Estado de Sao Paulo, foram tomadas, em um periodo de dois anos, 28 amostras da fauna de fundo, utilizando-se redes tipo ottertrawl abrangendo a area compreendida entre as ilhas Anchieta, Vitoria e das Couves. A despeito do pequeno tamanho das redes - 30 pes na tralha de boia -, os resultados, quanto a numero e diversidade dos peixes encontrados na area, pareceram ser muito significativos e justificar a comunicacao atual. Um total de 97 especies de peixes, tanto osseos quanto cartilaginosos, foi obtido em 28 capturas controladas, durante os anos de 1978 e 1979, A familia melhor representada foi, como previsto, a dos Sciaenidae; porem, representantes de Rajidae, Bothidae e Cynoglossidae foram tambem abundantes. Lophius gastrophysus e Merluccius hubbsii, ocorreram apenas em profundidades acima de 30 m, o que concorda com sua distribuicao conhecida na costa do extremo sul do pais, Uma lista sistematica das especies e seus nomes populares, quando disponiveis, e dada.

Anelídeos Poliquetos da costa Brasileira: 5. Pisionidae, Chrysopetalidae, Amphinomidae e Euphrosinidae

This isthe fifth fascicle of the series and deals with the polychaete families Psionidae, Chrysoptelidae, Aniphinomidae e Euphrosinidae whieh are represented in the Brazilian coast respectively hy 1,5, 9 and 2 species. The speciniens of ali the species examined are deposited in the Collection of the Departamento de Zoologia, Instituto de Biologia of the Universidade Estadual de Campinas (UNICAMP), Campinas, Sao Paulo.