The Serra da Mantiqueira, south-eastern Brazil, as a biogeographical barrier for fishes

To present a fish fauna survey from rivers draining the south-western region of the Serra da Mantiqueira, and to investigate the effectiveness of that mountain range as a biogeographical barrier isolating the fish faunas of the Paraiba do Sul basin and the upper Parana river. Location Six drainages from the south-we stern portion of the Serra da Mantiqueira in the region of Campos do Jordao, Brazil, were studied. They included three drainages belonging to the Paraiba do Sul basin (Piracuama, Grande and Buenos), and three belonging to the Sapucai basin, Rio Parana system (Sapucai-Mirim, upper Sapucai and Santo Antonio). Methods The survey was conducted in two sampling trips supplemented by examination of specimens preserved in museum collections. Parsimony analysis of endemicity (PAE) was used to detect the hierarchy of relationships among the six drainages. Results A total of 47 species of fishes was recorded in the six drainages. The main watershed divide is an effective barrier between the two basins, with 28 species occurring exclusively in the Paraiba do Sul versant, and 15 occurring exclusively on the slope of the Sapucai basin. The PAE of 18 species with cladistically informative distributions and unproblematic taxonomic diagnoses produced a single area cladogram, with complete congruence among 14 species. Main conclusions The main Mantiqueira watershed divide is an effective biogeographical barrier isolating the fish faunas of the Paraiba do Sul and the Sapucai basin (upper Parana system). Previous hypotheses of a past connection between the upper Parana and the Paraiba do Sul are not supported by extant species distributions in the Serra da Mantiqueira region. Within-basin drainage differentiation, however, is relatively low.