A piranha has shark-like teeth and an impressive bite for its size, and it feeds on a variety of food. The name "piranha" comes from the native Tupi language in Brazil meaning "tooth fish."
The piranha has teeth that are similar to a shark's teeth in enamel structure. Like sharks, this fish also replaces missing teeth throughout its life; however, teeth are replaced in sets rather than individually. Its jaw can exert 72 pounds per square inch, which is three times the body weight of the largest piranhas. The piranha's ancestor from 10 million years ago was able to bite at 1,068 pounds per square inch, which was 50 times its body weight.
Although many species of piranha feed on other fish, meat and even each other, there are some species that feed almost entirely on seeds and plants. One species that lives in the Trombetas basin in Brazil eats only river weeds.
The piranha has a fierce reputation largely because of Theodore Roosevelt, who witnessed piranhas stripping a cow of flesh in just minutes, then wrote down the tale; it became a part of legend. In reality, before Roosevelt showed up in South America, the natives captured and starved the fish before returning them to the river and throwing in a cow carcass.