Serrasalmidae
Serrasalmidae is the family of piranhas. All are native to South America. It includes several living genera like Serrasalmus, and an extinct genus called Megapiranha.
Description
Piranhas have sharp teeth. A pycnodont called Piranhamesodon has teeth resembling a piranha. The bluefish is called the marine piranha because of its teeth.
Taxonomy
The Serrasalmidae were recently classified as a subfamily of the Characidae. However, the classification of these fish is still not certain. Despite this, the Serrasalmidae are relatively well understood. The genera and species are widely agrees.
Fossil record
The fossil record, particularly for piranhas, is relatively sparse. Most known fossils are from the Miocene. Two were in the Upper Cretaceous.
Relationship to humans
Many serrasalmids are in demand as aquarium ornamentals, and several such as Piaractus and Colossoma, are economically important to commercial fisheries and aquaculture.
Piranhas are generally less valued, although they are commonly consumed by subsistence fishers and frequently sold for food in local markets.