Distribuição espacial e estrutura da comunidade de crustáceos de águas intersticiais de um igarapé amazônico e um riacho da mata atlântica / Spatial distribution and structure of interstitial water crustacean assemblages in an Amazonian stream and an Atlantic forest stream

AUTOR(ES)

Luciana Paes de Andrade

DATA DE PUBLICAÇÃO

2007

RESUMO

The assemblages of the copepod fauna from interstitial waters in the hyporheic zones from a stream in Central Amazon and a stream in the Atlantic rainforest of southeastern Brazil were compared in terms of composition, diversity and organism distribution. The relation of the identified species with abiotic factors was analyzed, aiming at establishing which factors were determinant for their distribution. The abiotic factors analyzed were: temperature, pH, dissolved oxygen, and sediment granulometry. In thick sand, there is predominance of copepodites and of the genus Forficatocaris (one species found in the Atlantic rainforest and two new species in the Amazon). These three species of Forficatocaris and the copepodites explore the same kind of microhabitat in the sediment. When medium size of sand grains prevail, there is an increase in the presence of other genera, such as Potamocaris (one species for the Atlantic rainforest and one new species for the Amazon) and Parastenocaris (Atlantic rainforest), besides a decline in number of copepodites. There is a direct ratio between the temperature and the distribution of microcrustaceans, with a predominance of these invertebrates in lower temperatures. There are significant differences in pH values when both localities (Amazon and Atlantic rainforest) are compared; however, comparisons between seasons (lower rainfall versus rainy periods) in a same location did not yield differences. It is suggested that the pH influences species composition, but not species distribution. There is a similar number of species inhabiting both environments and a distribution pattern for the hyporheic fauna. These similarities point at the existence of patterns in the structure and behavior in these natural communities of interstitial microcrustaceans, molded by similar selective pressures.

ASSUNTO(S)

copepoda crustacea harpacticoida harpacticoida crustacea fauna intersticial copepoda interstitial fauna

Documentos Relacionados

• Spatial distribution of bryophytes across the Atlantic Forest, southeastern Brazil
• Distribuição de oligoquetas em um riacho da Mata Atlântica, Sudeste do Brasil
• Composição e distribuição espacial e sazonal de anfíbios em unidade de conservação da Mata Atlântica, Alfredo Chaves, Espírito Santo
• Riacho de montanha, Mata Atlântica, Paraná, Brasil: caracterização e estrutura trófica
• Fatores abioticos e variação espacial na estrutura da floresta ombrofila densa atlantica