Iguanodectidae

Bryconops is a genus of freshwater ray-finned fish in the family Iguanodectidae from South America. It consists of small fish, all under half-a-foot long, with slender bodies and silvery scales, though there is some mild color variation. Several species can be identified by way of a humeral patch (a mark near the pectoral fin), and others have a reddish ocellus, or eyespot, on one or both lobes of the dorsal fin.

Iguanodectes is a genus of freshwater ray-finned fish belonging to the family Iguanodectidae. The fishes in this genus are found in tropical South America. They are all small tetras, none longer than 5 inches, and often have attractive silvery or striped scales, which makes them a target for the ornamental fish industry. Alongside the genus Piabucus, it has been treated as belonging to the subfamily Iguanodectinae, which in turn is in the family Iguanodectidae, although this is not universally recognised.

Piabucus is a genus of freshwater tetras in the family Iguanodectidae. All three species are found in South America, largely the Amazon and its major tributaries. None of them are longer than half a foot long, with the largest reaching a maximum size of , and they are slender, with relatively deep chests and long pectoral fins. Their scales are pale or silvery, with lateral lines that stand out.

Iguanodectidae is a family of freshwater fish in the order Characiformes that lives in South America. It contains three genera: Iguanodectes, Piabucus, and Bryconops. Several species in the family, such as the green line lizard tetra (Iguanodectes spilurus), the tailspot tetra (Bryconops caudomaculatus), and the orangefin tetra (Bryconops affinis), are sometimes taken as aquarium fish.