We examined the composition, richness and biomass of fish assemblages associated with aquatic macrophytes in temporary environments of the Pantanal de Poconé, State of Mato Grosso, Brazil. The fish were captured in April 2008 in five loan boxes and five locations along Coqueiro Bay, using seine nets at three points within each site. A total of 9646 specimens were captured, distributed in seven orders, 17 families and 59 species. The fish community was composed mainly of small-sized species (Characidae) and some juveniles of medium-sized species (Erythrinidae and Gymnotidae). In this study, few species were very abundant, some showed intermediate abundance, and most had low abundance. According to an analysis of similarity (Anosim) there was no difference in species composition between the environments. Species richness, total abundance and biomass did not vary spatially. Thus, the results suggest that the similarity of the fish fauna can be attributed to flooding, since this phenomenon homogenizes the abiotic characteristics and enlarges the area for the distribution of fish. This fact seems to be very important for these small fish species, since many species need to inhabit specific sites during certain stages; for example, these environments may function as temporary refuges. This aspect may ensure the survival of many individuals until they reach a stage in life where predation is significantly reduced.
temporary habitats; species composition; ichthyofauna; similarity; flooding
