Hypostomus regani (Ihering, 1905)

Fig. 24

Body deep; greatest body depth contained 4.3 to 4.7 and caudal peduncle depth 9.3 to 10.3 times in SL; head length 3.1 to 3.4, predorsal distance 2.5 to 2.8, dorsal-fin spine length 2.2 to 3.6, pectoral-fin spine length 3.1 to 3.7, adipose-fin spine length 10.0 to 13.3 and caudal peduncle length 2.8 to 3.3 in SL; snout length 1.6 to 1.8, horizontal orbital diameter 4.8 to 5.8 and least interorbital width 2.3 to 2.6 in HL. Mouth inferior; premaxilla with 65-110 and dentary with 65-132 teeth. Mid-lateral series with 27 or 28, predorsal series with 3-5, and dorsal-fin base series with 8 or 9 plates. Dorsal fin with I,7, pectoral fin with I,6, pelvic fin with i,5 and anal fin with 6 rays. Ground color brown; lightbeige spots on body, smaller on head. Dark-brown fins with light-beige spots.

Maximum standard length. 280.0 mm (Graça, Pavanelli, 2007).

Distribution. Río de la Plata basin.