Piabucus

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.

At least one species, Piabucus dentatus, is known to be collected for the aquarium industry. All three species are sometimes given the collective name "chin tetras" by sellers, in reference to markings on the lower jaw. However, none of the species are considered endangered, so capture of wild specimens is not an immediate threat to population numbers. As well as this, collection is not happening at a high enough rate to be of any concern.