Deep laterally compressed bodies are generally silvery or golden in color, with a short adipose fin, jaws with a single row of sharp tricuspid sheering teeth and no molars. Other characids look somewhat similar but can be distinguished primarily by the dentition. Pacus (Colossoma spp.), and silver dollars (Metynnis spp.) as well as Myleus spp. and Mylossoma spp. have molar-like teeth used for crushing food. In telling Piranhas from Metynnis and other silver dollars, the angle of the jaw is a pretty good characteristic for sorting them...forward jutting lower jaw that forms a V at the angle is a piranha, even upper and lower jaw profile that forms a U at the angle of the jaw is not a piranha.
Predatory, with their dentition they are able to bite pieces out of larger prey, as opposed to having to swallow their prey whole, as do most North American freshwater fishes. Often feed in schools and exhibit feeding-frenzy behavior.
Age and Growth
Most less than 2 pounds but up to 16 inches and 6 pounds.
Fishing Tips and Facts:
The entire subfamily Serrasalminae is prohibited in Florida due to its predatory nature, human safety concerns and their proven ability to spawn and survive in south Florida.
Florida Fish and Wildlife Conservation Commission (FWC) receives occasional reports of piranha being caught, but they almost always turn out to be a very similar-looking non native fish, called Pacu (Colosomma spp.), which look similar to piranha but have molar-like teeth and grow to much larger sizes. Due to their popularity in the aquarium industry, individual pacu have been collected a number of times from Florida waters.
Pacu (Colosomma spp.) look similar to piranha but have molar-like teeth and grow to much larger sizes. Due to their popularity in the aquarium industry, individual pacu have been collected a number of times from Florida waters.
Silver dollars are another group of characids that superficially resemble piranha but are primarily herbivorous with molar-like teeth.
Image Credit: FWC