Stygichthyinae

species of fish

Deuterodon is a genus of characins from river basins in southern and southeastern Brazil (Rio Grande do Sul to Espírito Santo), with a single species of uncertain taxonomic status, D. potaroensis, from Guyana. These are small fish that reach up to in total length. They are omnivores with a specialized mouth structure that allows them to scrape algae and debris off bedrock.

Coptobrycon is a monospecific genus of freshwater ray-finned fish belonging to the family Acestrorhamphidae, the American tetras. The only species in this genus is Coptobrycon bilineatus, a species which is endemic to Brazil, where it is known to occur in the upper Tietê River basin and in coastal basins that drain the Serra do Mar near the municipalities of Mogi das Cruzes and Bertioga in São Paulo state. It is found in clear water with abundant aquatic vegetation and submerged tree trunks, where it lives in shoals. Its diet is mainly plant matter, with some animals eaten as well. It appears