Agoniates is a genus of slender, silvery predatory characins, distinct from the tetra-sized fish most aquarists picture in the order Characiformes. The common name 'anchovy characin' captures the look: an elongated, laterally compressed body with a strongly upturned mouth built for snapping prey and insects near the surface, more reminiscent of a marine anchovy or herring than a typical freshwater tetra. The atlas covers 2 species, 6–10.5 in as adults, found across a wide swath of the Amazon and Orinoco basins in Brazil, Bolivia, Colombia, Ecuador, Guyana, Peru, and Venezuela.
Neither Agoniates anchovia nor Agoniates halecinus is a regular aquarium fish; their size, predatory habits, and need for open swimming space put them outside typical community-tank keeping, and they are best understood as part of the Amazon and Orinoco's natural fish fauna rather than trade species. Both are assessed Least Concern, consistent with a genus that ranges across large, still relatively intact river systems.