A influência do ambiente e do espaço em comunidades de peixes estuarinos da Zona Costeira Amazônica

Abstract

One of the objectives of fish assemblage ecology is to identify and predict the structuring patterns of these assemblages in response to biotic and abiotic interactions that occurs within the ecosystem. Specifically at the Amazon Coastal Zone there is growing number of studies being made about the influences of the environment and geographic location structuring estuarine fish assemblages, however, these influences have been evaluated separately, leaving incomplete the understanding of the dynamics within these environments. Therefore, this study aimed to identify the space-seasonal structuring pattern the ichthyofauna at Salinópolis Bay linking assemblage descriptors of fish assemblages with environmental and spatial variables. The sampling period took place on the rain and dry seasons of 2011 within the Salinópolis Bay using traditional sampling methods (bottom fish nets). A total of 1,294 indivuals were captured, distributed in 67 species and 27 families. Species Cathorops spixii (n = 121) and Cathorops agassizii (n = 201) were the most abundant during the rainy season. During the dry season, species Cathorops agassizii (n = 118) and Genyatremus luteus (n = 72) were most abundant. Results shown that fish diversity between seasons are very similar. The environmental and geographic variables do not influence the structure of the fish assemblage, suggesting a random pattern of distribution for this assemblage, following the null model pattern.