Hemisorubim platyrhynchos (Valenciennes, 1840)

Fig. 28

Body elongated; greatest depth contained 6.5 to 7.6, head depth 10.6 to 10.9, caudal-peduncle depth 14.7 to 15.8 times in SL; head length 2.9 to 3.4, anal-fin base length 12.1 to 12.3, adipose-fin base length 7.0 to 7.9, maxillary-barbel length 1.8 to 2.0 in SL; snout length 2.0 to 2.6, horizontal orbital diameter 5.5 to 5.8 and least interorbital width 4.8 to 5.4 in HL. Mouth prognathous, dentary slightly prognathous; dentigerous tooth plates present in both premaxilla and dentary. Dorsal fin with 7, pectoral fin with 11-16, pelvic fin with 7 and anal fin with 10-14 rays. Ground color yellowish-green; one or two black rounded blotch on flank; sometimes one black spot on superior portion of caudal peduncle. Yellowish fins, with or without dark-grey diffuse blotches (Graça, Pavanelli, 2007).

Maximum standard length. 495.0 mm (Graça, Pavanelli, 2007).

Distribution. Amazon and río Orinoco basins and Paraná- Paraguay system.