Peixes da planície de inundação do alto rio Paraná e áreas adjacentes: revised, annotated and updated Author Ota, Renata Rúbia Author Deprá, Gabriel de Carvalho Author Graça, Weferson Júnio da Author Pavanelli, Carla Simone text Neotropical Ichthyology 2018 2018-06-11 16 2 1 111 journal article 10.1590/1982-0224-20170094 f68fe85c-2a4c-4625-b684-74f61398d6c2 1982-0224 3678395 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.