Red-bellied piranha

Described in 1858 by Rudolf Kner, the red-bellied piranha is named after the Austrian naturalist Johann Natterer, who explored Brazil for eighteen years. Pygocentrus means “spiny rump”, for the serrated keel on its belly. Its sharp triangular teeth are replaced in sets, alternately on each side of the jaw.

Its reputation as a man-eater is largely a myth, born notably during Theodore Roosevelt's journey to Brazil in 1913–1914: piranhas that had been starved for weeks in a closed-off river arm devoured a cow before his eyes. It also produces sounds, a kind of barking, with its swim bladder.

It occupies much of the Amazon basin, the Essequibo, coastal rivers of north-eastern Brazil and the Guianas, and further south the Paraná and Uruguay basins; the type locality is Cuiabá, in Mato Grosso.

It lives in almost every habitat: large channels, tributaries, oxbows, floodplain lakes and even reservoirs. It breeds twice a year, among the vegetation of flooded banks.