Fábio Vieira

A new species of Leporinus (Characiformes: Anostomidae) is described from tributaries of the upper rio Jequitinhonha basin, eastern Brazil, based on morphological and molecular evidence. The new species is distinguished from congeners by the unique combination of three premaxillary and four dentary teeth, 12 scale rows around the caudal peduncle, three large dark midlateral blotches on the body, and a conspicuous red spot on the posterior portion of the upper lip. It is further characterized by its reduced body size, with the largest known specimen reaching only 128.6 mm of standard length, an uncommon condition among anostomids. DNA barcoding analyses (COI) revealed genetic divergences ranging from 3.8% to 8.5% from its closest congeners (L. microphthalmus and L. amblyrhynchus) and consistently recovered all specimens of the new species as a distinct Molecular Operational Taxonomic Unit. Phylogenetic analyses placed the new species within the L. melanopleura clade, together with L. amblyrhynchus, L. melanopleura, L. melanopleurodes, and L. microphthalmus. The species is endemic to a restricted area of the rio Jequitinhonha basin, where its populations are likely severely fragmented and threatened by multiple anthropogenic impacts. The discovery of this small-sized anostomid adds to the growing evidence of high levels of endemism and conservation concerns in eastern Brazilian coastal drainages.

This work was carried out from the assessment of the conservation status of the freshwater ichthyofauna from Bahia State. The inventory data and species distribution were obtained from the specialized scientific literature and representative ichthyological collections. A total of 281 native species was recorded in Bahia State, distributed in the Northeastern Mata Atlantica (NMA) and São Francisco (SFR) freshwater ecoregions. There was a larger number of species in the NMA (187 spp.), composed by several coastal basins, than in the SFR (134 spp.), composed by São Francisco river basin. Among the 30 families recorded, Characidae and Rivulidae were the most representative, with 53 and 48 species, respectively. The conservation status of 214 species was assessed and 33 of them (15%) were included in the IUCN threat categories. Of these, 11 species were classified as vulnerable (VU), 12 as endangered (EN), and 10 as critically endangered (CR). Most threatened species (n = 14) belongs to the family Rivulidae. The larger number of threatened species in the NMA: (n = 23) is mainly related to the high endemism of restricted-range species associated with the human occupation impacts along the coastal regions. In the SFR, most of threatened species are annual killifishes, which are locally disappearing due to increasing degradation of their temporary habitats.