Stoplight Tetra Tetragonopterus argenteus

The Stoplight Tetra is native to the Amazon, upper Essequibo, Orinoco, Parnaíba, Jaguaribe, Paraguay and lower Paraná river basins (from Ecuador and Bolivia across to Venezuela and south to Brazil and Paraguay). Living in small groups, they grow quite large for tetra, to 11-12 cm long. Their scientific name Tetragonopterus, four-sided shape with wings/fins, was the origin of the word Tetra for the fish and there used to be many put into that genus that have now been moved out to other genera.