Found in eastern and central South America, including the Southeast of Brazil, northern Argentina, Uruguay, Paraguay, and Bolivia. It is generally found in still or slow-moving water, located in freshwater marshes, swamps, and mangroves and will readily use man-made cow ponds.

Generally, growing to 2-2.5m, males have been recorded 3.5m in length. In captivity, they have been found to weigh 23-65kg as adults, though large males of 2.6m usually exceed 80kg.

Relying on external temperature to regulate its body temperature. They feed on small invertebrates, and can crush shells to eat turtles and snails. As they grow they increase the number of birds fish amphibians and reptiles that they will eat as well.

Hunting started in the 1940s, as its skin is valued for its smooth texture. Thankfully, hunting has been banned in most countries and numbers are recovering. It is considered endangered.

The population is estimated at 250,000-500,000.