or coypu Semiaquatic South American rodent (Myocastor coypus) in the hutia family (Capromyidae). The nutria has small ears, a long, rounded, scaly tail, partially webbed hind feet, and broad orange incisors. It is about 40 in. (1 m) long, including the tail, and may weigh 18 lbs (8 kg). Its reddish brown fur consists of coarse guard hairs overlying a soft undercoat. The nutria lives in a shallow burrow along a pond or river and mainly eats aquatic plants. Because their fur is valuable, nutrias were introduced into North America and Europe, and in some places have become pests that damage crops and compete with other wildlife