Anostomidae

The Anostomidae are a family of ray-finned fishes that belong to the order Characiformes. Closely related to the Chilodidae and formerly included with them, the Anostomidae contain about 150 described species. Commonly known as anostomids, they are found in freshwater habitats from the Río Atrato in northernmost South America to warm-temperate central Argentina; they are of Amazon origin, with few found west of the Andes (mainly in Colombia and Venezuela). Their scientific name approximately means "mouth on top", from Ancient Greek áno- (ἄνω) "up" (as an adverb) + stóma (στόμᾶ) "mouth", in ref

Leporellus is a genus of headstanders found in South America. They are mainly found in the São Francisco River and Paraná–Paraguay river basins, but L. vittatus also occurs in the Amazon. There are currently four described species in this genus.