Pimelodella gracilis (Valenciennes, 1835)

Fig. 22

Body elongated; greatest body depth contained 5.1 to 5.9, head depth 4.2 to 4.9 and caudal peduncle depth 7.2 to 7.9 times in SL; head length 4.3 to 5.0, anal-fin base length 6.4 to 7.8, adipose-fin base length 2.3 to 2.5 and maxillarybarbel length 1.2 to 1.5 times in SL; snout length 2.3 to 2.5, horizontal orbital diameter 3.0 to 3.3 and least interorbital width 3.7 to 5.0 times in HL. Mouth terminal; premaxilla and dentary with several diminute and viliform teeth. Dorsal fin with I,6, pectoral fin with I,9 or 10, pelvic fin with 6 and anal fin with 12-14 rays. Ground color beige; dark-brown longitudinal band along lateral line. Hyaline fins (Graça, Pavanelli, 2007).

Maximum standard length. 184.0 mm (Graça, Pavanelli, 2007).

Distribution. Río de la Plata, Amazon and río Orinoco basins.