Leporinus

1. Twelve circumpeduncular scale rows ... L. amblyrhynchus

1’. Sixteen circumpeduncular scale rows............................ 2

2. Flank with four dark-brown longitudinal bands...... L. striatus

2’. Flank with no dark-brown longitudinal bands............... 3

3. Flank with dark-brown transverse bars........................... 4

3’. Flank with no dark-brown transverse bars, usually with black or dark-brown rounded blotches ............................... 5

4. All dark-brown bars simple; pelvic fin with nine rays ................................................................. L. octofaciatus

4’. At least some of the dark-brown bars Y-shaped; pelvic fin with 10 rays ...................................................... L. tigrinus

5. Lateral line with 33 to 35 pored scales; three black or dark-brown rounded blotches on flank, the first larger and more conspicuous than the others ....................... L. lacustris

5’. Lateral line with 37 to 44 pored scales; three black or dark-brown horizontally elongated blotches on flank, equally pigmented................................................ L. friderici