Hypostomus cochliodon Kner, 1854

Fig. 23

Body deep; greatest body depth contained 3.7 to 4.0 and caudal peduncle depth 9.1 to 10.4 times in SL; head length 3.7 to 4.1, predorsal distance 3.2 to 3.4, dorsal-fin spine length 3.7 to 4.1, pectoral-fin spine length 3.2 to 3.4, adipose-fin spine length 12.8 to 17.0 and caudal peduncle length 3.0 to 3.4 in SL; snout length 1.4 to 1.6, horizontal orbital diameter 6.1 to 6.3 and least interorbital width 1.8 to 2.0 in HL. Mouth inferior; premaxilla with 7 and dentary with 8 teeth. Mid-lateral series with 27 or 28, predorsal series with 3, and dorsal-fin base series with 8 plates. Dorsal fin with I,7, pectoral fin with I,6, pelvic fin with i,5 and anal fin with 6 rays. Ground color brown; dark-brown blotches on body, more conspicuous on head. Brown fins with black spots.

Maximum standard length. 270.0 mm. (Graça, Pavanelli, 2007).

Distribution. Río Paraguay and middle río Paraná basins.

Remarks. Hypostomus cochliodon is a non-native species from the upper rio Paraná, and its occurrence can be associated with the filling of the Itaipu Reservoir and the consequent inundation of the Sete Quedas Falls.