DistribuiÃÃo dos copepoda harpacticoida da meiofauna em Ãrea de talude no litoral de Sergipe, Brasil

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

The study of the composition, abundance and diversity of Copepoda Harpacticoida in the slope of Sergipe, was conducted using samples obtained in April 2002 with three replicates during the Oceanographic Campaign NE2002-C1 (project FADURPE / CENPESPETROBRAS No 50.0003502.04.2). The studied stations were organized by: isobaths - 100m (stations 1, 2 and 3), 500m (stations 4, 5 and 6), 900m (stations 7, 8 and 9) and 1.300m (stations 10, 11 and 12); strata or depth within the sediment - 0-2 and 2-5cm; and transects: north (stations 1, 4, 7 and 10), center (stations 2, 5, 8 and 11) and south (stations 3, 6, 9 and 12). The north and south transects are associated with canyon features that do not occur in the Center transect. In the field, the animals were fixed with 10% buffered formalin. In the laboratory, Harpacticoida were separated from the interval of 0,044 to 0,5mm mesh size and identified. Data on environmental parameters (CaCO3, organic matter, percentage of sand, silt and clay, salinity and temperature) were furnished by PETROBRAS. A hundred and sixtyfour species were identified belonging to 101 genera and 28 families. Miraciidae family was the most abundant (21,4%), followed by Ectinosomatidae (14,2%) and Cletodidae (11,5%). A total of 59 genera were recorded for the first time for Brazil and from the 79 identified species more than 90% are new to science. The average density of Harpacticoida in the stratum of 0-2cm varied from 0,2 to 14,5 ind.10cm-2 at stations 12.2 and 6.3 respectively. In the 2-5cm stratum, the density varied from 0,1 ind.10cm-2 (stations 3.3, 7.3, 11.2, 12.2) to 6,1 ind.10cm-2 (station 6.1). Considering isobaths, the average density varied from 3 to 7,5 ind.10cm-2, for depths of 1.300 and 500 m respectively. In the studied transects, the density varied from 3,6 (north) to 6,5 ind.10cm-2 (center). Seventy-three percent of Harpacticoida individuals occurred in surface sediment (0-2cm). The diversity was higher at the center (no canyons) with an average of 2,3 nat (Tukey, p = 0,035) compared with the north (average of 1,89 nat). Richness was higher at the center with an average of 19 species (Tukey, p = 0,018) compared with the north (average of 9,8). In relation to diversity no significant difference was detected among isobaths. The BIO-ENV indicated isobath (rs = 0,346) as the factor that better explained the variation of the association of Harpacticoida. The species Pseudomesochra longiseta sp. nov. and Kliopsyllus minor sp. nov. are described.

ASSUNTO(S)

harpacticoida sergipe atlantic ocean oceanografia harpacticoida oceano atlÃntico taxonomia sergipe taxonomic

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