Hypopygus cryptogenes
Hypopygus cryptogenes is a species of bluntnose knifefish endemic to Brazil where it is found in the Rio Negro basin. This species can reach a total length of up to. It is the only member of the genus Stegostenopos according to FishBase, but studies have shown that it belongs in Hypopygus and this is followed by the Catalog of Fishes.