Rhamdia quelen (Quoy, Gaimard, 1824)

Fig. 22

Body elongated; greatest body depth contained 4.7 to 5.7, head depth 6.7 to 9.0 and caudal peduncle depth 5.6 to 8.4 times in SL; head length 4.1 to 4.2, anal-fin base length 7.8 to 8.8, adipose-fin base length 2.3 to 2.7 and maxillary-barbel length 2.1 to 2.7 times in SL; snout length 3.0 to 3.1, horizontal orbital diameter 5.6 to 6.1 and least interorbital width 3.0 to 3.1 times in HL. Mouth terminal; premaxilla and dentary with several diminute and viliform teeth. Dorsal fin with 7, pectoral fin with 8-10, pelvic fin with 6 and anal fin with 14-15 rays. Ground color beige to brown; some specimens can present scattered dark-brown chromatophores on body. Dark-grey or brown fins (Graça, Pavanelli, 2007).

Maximum standard length. 410.0 mm (Graça, Pavanelli, 2007).

Distribution. Widespread in South America rivers.