Composition and temporal variation of the fish assemblages in upper Santos estuarine system, São Paulo, Brazil

Abstract

To evaluate the composition and temporal variation of a fish community of the upper Santos estuarine system in Brazil, a sampling program was organized with set gillnets positioned near Bagres Island for 24 h, in summer and winter of 2010. A total of 1,738 individuals belonging to 13 orders, 28 families and 59 species were captured. The most abundant families were Gerreidae and Sciaenidae. The most abundant species were Diapterus rhombeus, Harengula clupeola, Atherinella brasiliensis and Bairdiella rhonchus. This survey adds 17 species to those already known for this estuarine system. The overall species composition varies between day and night and between sites. There was a greater abundance of fish at night. The Shannon-Wiener diversity was found to be higher in the rainy season and at night. Ten species are categorized as "Endangered" according to the list of Species of Endangered Wildlife of the State of São Paulo.