Hypostomus margaritifer (Regan, 1908)

Fig. 24

Body deep; greatest body depth contained 4.1 to 4.5 and caudal peduncle depth 9.3 to 10.0 times in SL; head length 3.0 to 3.4, predorsal distance 2.4 to 2.7, dorsal-fin spine length 2.3 to 3.1, pectoral-fin spine length 2.6 to 3.1, adipose-fin spine length 13.5 to 16.0 and caudal peduncle length 2.9 to 3.6 in SL; snout length 1.4 to 1.6, horizontal orbital diameter 5.6 to 6.5 and least interorbital width 2.4 to 3.0 in HL. Mouth inferior; premaxilla and dentary with 19-32 teeth. Mid-lateral series with 26 or 27, predorsal series with 3, and dorsal-fin base series with 8 plates. Dorsal fin with I,7, pectoral fin with I,6, pelvic fin with i,5 and anal fin with 6 rays. Ground color dark-brown or -grey; light-beige spots and blotches on body. Dark-grey fins with light-beige spots.

Maximum standard length. 312.0 mm (Graça, Pavanelli, 2007).

Distribution. Upper rio Paraná basin.