The nutria, Myocastor coypus, is a large semi-aquatic rodent. The generic name is derived from two Greek words (mys, for mouse, and kastor, for beaver) that translate as mouse beaver. The specific name coypus is the Latinized form of coypu, a name in the language of the Araucanian Indians of south-central Chile and adjacent parts of Argentina for an aquatic mammal that was possibly this species.
