SPACE-TEMPORAL ORGANIZATION OF DEMERSAL FISH ASSEMBLAGES IN BRAZILIAN ESTUARINE ECOSYSTEMS: A SYNTHESIS

Abstract

Twenty two Brazilian estuarine locations with published lists of their respective inhabiting fish species, were studied in preparing the present paper. They geographically varied from equatorial environments (the Amazonian estuary in Para State) to subtropical envorironments (Arroi-Chui estuary in Rio Grande do Sul State). A total of 304 demersal teleost species belonging to 83 families were listed to these systems. The following familes, in this order, were represented by a greater number of species: Sciaenidae, Gobiidae, Serranidae, Ariidae, Haemulidae, Gerreidae, Paralichthyidae and Syngnathidae. These species were grouped according to their life strategies as: estuarine opportunists (54.3%), freshwater fish (14.9%), estuarine-dependent fi sh (13.2%), estuarine-dwelling fi sh (9.9%), diadromous fi sh (2.6%) and fish with unknown life histrories (5.0%). Only 11 species were common to all examined estuarine localities and the estuarine-dwelling Gobionellus oceanicus (Gobiidae) presented the greatest range of different habitats. From comparison, it seems that with the geographical range of the different fish species depend heavily on their individual spatial heterogeneity and tolerance to salinity and not so much on their mode of life.