new species from Argentina:
Heptapterus mbya Azpelicueta, Aguilera & Mirande, 2011

distribution and habitat (from publication):
Heptapterus mbya sp. n. is found in the Cuña-Pirú, Moreno, and Azul streams. The three streams are located in the río Paraná basin in Misiones, Argentina; the latter two, though, are headwaters of the Garuhapé stream. The largest number of specimens were collected in a pond about 1 m deep, with a slow current, and a sandy bottom; the place was bordered by dense vegetation, completely covered by shadow. The parameters measured were temperature at 18-20 °C, conductivity= 81μS/cm, and pH= 6.3.

published in:
Azpelicueta, M., G. Aguilera & J.M. Mirande (2011):
Heptapterus mbya (Siluriformes: Heptapteridae), a new species of catfish from the Paraná river basin, in Argentina.
Revue suisse de Zoologie 118 (2): 319-327

abstract (from publication):
We describe a new species of heptapterid catfish of the genus Heptapterus from the streams Cuña-Pirú, Azul, and Moreno, in the province of Misiones, Argentina. Heptapterus mbya sp. n. is distinguished from all other congeners by dark plumbeous body and a low number of anal-fin rays that are branched (11-12) out of a total number of 15-17 anal fin rays, a large eye (13.8-17.9 % of HL), prepectoral distance 31.9-37.8 % of SL, distance between the last dorsal-fin ray and the adipose-fin origin 5.24-8.33 % of SL, adipose fin base 47.4-58.5 % of SL, 13 principal caudal-fin rays, and 10-13 gill rakers on the first arch.