| Remarks |
Abstract: 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. |