An overview of the estuarine ichthyofauna from Bahia, Brazil: expanding the knowledge about the fish species of three important regions of the state

The coast of Bahia state is the longest along the Brazilian coastline, and there are significant knowledge gaps concerning its estuarine fish fauna. Thus, there is a need to provide extensive coverage of the estuarine ichthyofauna of Bahia to provide an updated checklist of its fishes, which could function as a database for the management of such biodiversity. Therefore, this study aimed to characterize three different important estuarine systems (Camamu, Todos os Santos Bay, and Caravelas) in Bahia to contribute information on the ichthyofauna in shallow areas of the state. We recorded 29 orders, 54 families, 101 genera, and 147 species of fish. The families with the highest number of species were Sciaenidae and Carangidae, with twelve and nine species, respectively, followed by Gobiidae and Engraulidae, each with eight species. In terms of abundance in the northern region, the orders Atheriniformes (28.80%), Pleuronectiformes (15.92%), Clupeiformes (14.20%), and Gerreiformes (13.91%) predominated. In the Central region, Gerreiformes (21.55%), Tetraodontiformes (17.94%), Gobiiformes (12.83%), and Clupeiformes (8.94%) were the most representative. In the southern region, the orders Clupeiformes (57.48%), Mugiliformes (14.09%), Atheriniformes (4.10%), Lutjaniformes (3.97%), Gerreiformes (3.60%), and Carangiformes (2.23%) predominated. The region was characterized by a high representation of guilds of marine migrant species, followed by marine, estuarine, and freshwater visitors.