Sternopygus

Sternopygus is a genus of glass knifefishes found in tropical and subtropical South America, and Panama. It is the only extant extant member of the subfamily Sternopyginae, with the related fossil genus Humboldtichthys also known from Bolivia.
They inhabit a wide range of freshwater habitats, from fast-flowing rivers to essentially static waters in floodplains, and shallow habitats to the bottom of deep rivers. S. macrurus will even visit brackish mangroves to feed.
They are medium to large knifefish, with a maximum total length of depending on the exact species. They feed on invertebrates, small fish and fruits. Most members of Gymnotiformes are nocturnal, but Sternopygus are both nocturnal and diurnal.

Species

There are currently twelve recognized species in this genus.

Sternopygus aequilabiatus
Sternopygus arenatus
Sternopygus astrabes Mago-Leccia, 1994
Sternopygus branco Crampton, Hulen & Albert, 2004
Sternopygus dariensis Meek & Hildebrand 1916
Sternopygus embera Torgersen, Galindo-Cuervo, Ortega-Lara, Lujan, Reis & Albert, 2026
Sternopygus macrurus
Sternopygus obtusirostris Steindachner, 1881
Sternopygus pejeraton Schultz, 1949
Sternopygus sabaji Torgersen & Albert, 2022
Sternopygus sarae Torgersen, Galindo-Cuervo, Reis & Albert, 2023
Sternopygus xingu Albert & Fink, 1996