Fishes from the rio da Dona, a threatened environment in the Recôncavo Sul basin, Bahia, Brazil

Abstract

The rio da Dona is an important water body in the Recôncavo Sul basin used as a water supply for the neighboring towns and for agriculture, recreation and subsistence fishing. The knowledge about the ichthyofauna of this river is scarce. In this paper, an inventory of the fish fauna from rio da Dona basin and an identification key for the species recorded are presented. Additionally, taxonomic and conservationist issues are discussed. The specimens were collected in different sites along the upper, middle and lower courses of the rio da Dona. The fishes were anesthetized, fixed in formalin, conserved in ethanol, and identified. In addition to the material collected, specimens previously deposited in the ichthyological collection of the Museu de História Natural da Bahia were also analyzed. Twenty species, distributed into 16 genera, ten families, and four orders were recorded. One of these species, Aspidoras kiriri, is endemic to the rio da Dona. Four species, Cichla pinima, Coptodon rendalli, Poecilia reticulata and Serrasalmus brandtii, have been introduced into the river. Higher richness of native species has been recorded in the upper course of the rio da Dona, while in the middle and lower parts non-native species were also representative. Along the river, a series of anthropic impacts were observed, such as deforestation of native forest including the riparian vegetation, silting and dams, which can probably compromised the resident ichthyofauna.