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 Pimelodus microstoma Steindachner, 1877 Fig. 29 Body deep; greatest body depth contained 4.1 to 5.2 times in SL; head length 3.5 to 3.9, anal-fin base length 7.5 to 11.7, adipose-fin base length 3.5 to 3.9, maxillary-barbel length 1.0 to 1.2 in SL; snout length 2.0 to 2.2, horizontal orbital diameter 3.8 to 5.1, and least interorbital width 4.0 to 6.0 in HL; orbital diameter 0.9 to 1.5 times in interorbital width. Mouth terminal; dentigerous tooth plates in both premaxilla and dentary. Dorsal fin with I,6, pectoral fin with 12-15, pelvic fin with 6, and anal fin with 11-14 rays ( Azpelicueta, 2001 ). Ground color greyish; eight or nine dark-brown longitudinal series of spots. Light-brown fins with few dark-brown spots, occasionally inconspicuous. Maximum standard length. 190.0 mm. Distribution. Upper rio Paraná basin. Remarks. Pimelodus microstoma was identified as P. heraldoi by Graça, Pavanelli (2007) . Ribeiro, Lucena (2010) proposed P. heraldoi as a junior-synonym of P. microstoma .