Two new species of the genus Leporinus has been described from the Araguaia-Tocantins River system in the Amazon basin: Leporinus unitaeniatus and Leporinus geminis.

Brazilian ichthyologists Julio Garavello and Geraldo Santos describe them both in a paper* published in the most recent issue of Brazilian Journal of Biology.

Leporinus unitaeniatus

Leporinus unitaeniatus derives its name from its distinguishing colour pattern; uni is the Latin word for one and taenia means ribbon. This fish is adorned with a conspicuous longitudinal dark brown bar along the lateral line on the flanks. Other distinguishing characteristics are the slender and elongated body, the narrow snout, and the small eyes. The mouth is sub-inferior and filled with elongated, incisor-like teeth forming a straight cutting edge. There are 42–44 lateral line scales; 6 scale rows above and 5 scale rows below the lateral line; and 16 circumpeduncular scales.

13f1 Two new species of Leporinus described from the Araguaia Tocantins River system
Picture credit: http://www.scielo.br

Leporinus geminis

Juvenile Leporinus geminis fish look very similar to juveniles of the close relative Leporinus unitaeniatus, hence the name Leporinus geminis. Geminius is the Latin word for twin.

Leporinus geminis is decorated with three large and vertically elongated brown blotches on the trunk and has one inconspicuous dark bar on the body. The body is deep, the snout is blunt, and the eyes are large. The mouth is sub-inferior and fitted with large incisor-like teeth forming a curved cutting edge. There are 40–42 lateral line scales; 5.5 or 6 scale rows above and 5 scale rows below the lateral line; and 16 circumpeduncular scales.

13f2 Two new species of Leporinus described from the Araguaia Tocantins River system
Picture credit: http://www.scielo.br

* Garavello, JC and GM Santos (2009) Two new species of Leporinus

Agassiz, 1829 from Araguaia-Tocantins system, Amazon basin, Brazil (Ostariophysi, Anostomidae). Brazilian Journal of Biology 69, pp. 109–116.