Species composition and abundance of shallow water fishes of five estuaries of Rio Grande do Sul State, Brazil

Abstract

It was compared the species composition and the abundance of shallow water fishes’ communities in five estuaries of Rio Grande do Sul State, Brazil. It was used a patronized methodology in the winter and summer sampling. In the captures it was used a 9 m beach seine trawl (1.2 m deep, 13 mm bar mesh in the wings and 5 mm in the center). The abundance was analyzed by CPUE. The Rio Grande do Sul estuaries are in a transitional area between the tropical places, on North, and in warm-temperate places, on South. This characteristic has an important influence on the shallow waters species composition. The Mampituba River, Tramandaí­­ River and Chuí­­ Arroyo estuaries were dominated by Mugilidae, while in Peixe Lagoon and Patos Lagoon estuarine areas the dominant family was Atherinidae. The abundance in estuaries looks to have relation with temperature latitudinal gradient and with the estuarine size.