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 .