Roeboides descalvadensis Fowler, 1932

Fig. 9

Body deep; greatest depth contained 2.2 to 2.7 and caudal peduncle depth 12.3 to 13.1 times in SL; head length 4.0 to 4.2, predorsal distance 1.9 to 2.0 and caudal peduncle length 12.8 to 13.5 in SL; snout length 3.6 to 4.4, horizontal orbital diameter 2.6 to 3.7 and least interorbital width 3.1 to 4.0 in HL. Mouth terminal; inner row of premaxilla with 6 teeth, outer with 4-6, inner row of dentary with 12-14, outer with 4-6 and maxilla with 9-11 teeth. Lateral line complete, with 66-71 pored scales; transverse series above lateral line with 13-16 scale rows and below with 8-10 scale rows. Dorsal fin with 10 or 11, pectoral fin with 11 or 12, pelvic fin with 9 or 10, anal fin with 50-55, and caudal fin with 19 rays. Ground color whitish; silvery longitudinal band on flank (brown or grey in preserved specimens), from humeral spot to caudal peduncle; black diffuse and oval, vertically elongated, humeral spot; one black spot on caudal peduncle, slightly forwarded prolonged. Yellowish fins (Graça, Pavanelli, 2007).

Maximum standard length. 100.0 mm (Graça, Pavanelli, 2007).

Distribution. Paraná-Paraguay system and Amazon basin.

Remarks. Roeboides descalvadensis was identified as R. paranensis by Graça, Pavanelli (2007). Lucena (2007) in a revisionary study of the Roeboides affinis (Günther, 1868) species-group, proposed the new synonym. Roeboides descalvadensis is a non-native species from the upper rio Paraná, and its occurrence can be associated with the filling of the Itaipu Reservoir and the consequent inundation of the Sete Quedas Falls (Júlio Júnior et al., 2009).