Os Nematoda da plataforma continental ao largo do sistema estuarino de Santos / Nematoda of the continental shelf off Santos estuarine system

AUTOR(ES)
FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

21/03/2011

RESUMO

To assess the influence of Santos estuarine system on the nematodes of the adjacent continental shelf, the density, composition and generic diversity of this group were analyzed and related to the sediment type, organic matter content and phytopigments biomass. The sediment was collected at six stations, in the winter of 2005 and summer of 2006, with a box-corer from which meiofauna samples were taken with a 4.9 cm2 superficial area and 10 cm height corer. Nematodes represented more than 95% of the total meiofauna, and their average densities were 2,472±1,794 ind.10cm-2 in the winter/2005 and 2,606±2,017 ind.10cm-2 in the summer/2006. The influence of Santos estuarine system was restricted to the closest areas to Santos bay and Bertioga channel and it was observed through the contribution of fine sediments and organic matter, which was more evident in the summer due to higher rainfall. In these areas, lower nematodes densities were found as higher abundance of deposit feeders genera, like Sabatieria and Terschellingia, and from the Xyalidae family. In the other shallow stations with well sorted sands and relatively high chlorophyll-a biomasses, densities were the highest and Chromadorita and Microlaimus, herbivorous/epistrate feeders, were predominant. In the deepest stations with finer sediments, the densities and diversities were the lowest and Sabatieria was dominant. Therefore, apart from the estuarine system, the depth and local hydrodynamics, which determines the sediment and trophic conditions, were important factors for the nematodes assemblages.

ASSUNTO(S)

: nematodes continental shelf ecologia ecology meiofauna meiofauna nematoda plataforma continental santos estuarine system. sistema estuarino de santos

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