About Rhaphiodon vulpinus Spix & Agassiz, 1829
Rhaphiodon vulpinus, commonly called the biara, is a dogtooth characin. It can reach a maximum recorded weight of 2.1 kg (4 lb 10 oz). While unconfirmed reports note individuals reaching up to 80 cm (2 ft 7 in) in standard length, the largest confirmed specimens measure 63 to 64 cm (about 2 ft 1 in). Like other dogtooth characins, the biara has very long, pointed canine teeth. It can be easily distinguished from its close relatives by its highly elongated, streamlined body shape. A study of the species' reproductive biology, conducted in the Tocantins River of Brazil, found that its primary reproductive period occurs in November. Increased reproductive rates in this species correspond with the river's annual high-water conditions.
