Descrição e osteologia de uma nova espécie do gênero Leporinus (Characiformes: anostomidae) do rio Xingu, Para, Brasil

Abstract

The fishes of the Anostomidae family are popularly known in Brazil as aracus, piaus and piaparas, being widely distributed in the Neotropical region, with more than half of the 150 known species concentrated in the Amazon. In the Xingu River, 23 species of Anostomidae are known, and the present study seeks to expand knowledge about the diversity of Anostomidae in the Xingu River basin, through the description of a new species, using traditional taxonomy tools and molecular markers, in addition to verify its distribution pattern and conservation status. The analyzed material comes from collections in the upper, middle and lower reaches of the Xingu River, and is deposited in the scientific collections of LIA, INPA, MZUSP, MPEG and MZUEL. A total of 56 individuals were analyzed. Leporinus sp.2 has a body with a longitudinal dark stripe that goes from the anterior portion of the operculum to the caudal peduncle, formed by horizontally elongated macules, dark transverse bars on the dorsum and 3/4 dental formula. It is similar in color pattern to L. britskii, L. guttatus, L. marcgravii, L. microphysus, L. unitaeniatus, L. vanzoi and L. octomaculatus. The new species differs from L. britskii, L. guttatus, L. marcgravii and L. octomaculatus by having 16 rows of scales around the caudal peduncle (vs. 12), from L. unitaeniatus, L. vanzoi by having three teeth on the premaxilla (vs, four). The DNA Barcode data also corroborate this hypothesis, since the new species differs from all analyzed congeners. The closest congeners of the new species are L. uniateiniatus and L. vanzoi, with whom it has a genetic distance of about 3%. Osteological characteristics of the species are described, illustrated and discussed.Osteological characteristics of the species are described, illustrated and discussed.