Coypu

The coypu (from Spanish coipú, from Mapudungun koypu; Myocastor coypus), also known as the nutria, is a large, herbivorous, semiaquatic rodent.Classified for a long time as the only member of the family Myocastoridae, Myocastor is actually nested within Echimyidae, the family of the spiny rats.The coypu lives in burrows alongside stretches of water, and feeds on river plant stems. Originally native to subtropical and temperate South America, it has since been introduced to North America, Europe, Asia, and Africa, primarily by fur farmers. Although it is still hunted and trapped for its fur in some regions, its destructive burrowing and feeding habits often bring it into conflict with humans, and it is considered an invasive species. The genus name Myocastor derives from the two Ancient Greek words μῦς (mûs), meaning 'rat, mouse', and κάστωρ (kástōr), meaning 'beaver'. Literally, therefore, the name Myocastor means 'beaver rat'. Two names are commonly used in English for Myocastor coypus. The name 'nutria' (from Spanish nutria) is generally used in North America, Asia, and throughout countries of the former Soviet Union; however, in most Spanish-speaking countries, the word 'nutria' refers primarily to the otter. To avoid this ambiguity, the name 'coypu' or 'coipo' (derived from the Mapudungun language) is used in Latin America and parts of Europe. In France, the coypu is known as a ragondin. In Dutch, it is known as beverrat (beaver rat). In German, it is known as Nutria, Biberratte (beaver rat), or Sumpfbiber (swamp beaver). In Italy, instead, the popular name is, as in North America and Asia, 'nutria', but it is also called castorino ('little beaver'), by which its fur is known in Italy. In Swedish, the animal is known as sumpbäver (marsh/swamp beaver). In Brazil, the animal is known as ratão-do-banhado, nútria, or caxingui (the last from the Tupi language). The coypu was first described by Juan Ignacio Molina in 1782 as Mus coypus, a member of the mouse genus. The genus Myocastor was assigned in 1792 by Robert Kerr. Geoffroy Saint-Hilaire, independently of Kerr, named the species Myopotamus coypus, and it is occasionally referred to by this name. Four subspecies are generally recognized: M. c. bonariensis, the subspecies present in the northernmost (subtropical) part of the coypu's range, is believed to be the type of coypu most commonly introduced to other continents. Comparison of DNA and protein sequences showed that the genus Myocastor is the sister group to the genus Callistomys (painted tree-rats). In turn, these two taxa share evolutionary affinities with other Myocastorini genera: Proechimys and Hoplomys (armored rats) on the one hand, and Thrichomys on the other hand. The coypu somewhat resembles a very large rat, or a beaver with a small tail. Adults are typically 4–9 kg (8.8–19.8 lb) in weight, and 40–60 cm (16–24 in) in body length, with a 30 to 45 cm (12 to 18 in) tail. It is possible for coypu to weigh up to 16 to 17 kg (35 to 37 lb), although adults usually average 4.5 to 7 kg (9.9 to 15.4 lb). They have coarse, darkish brown outer fur with soft dense grey under fur, also called the nutria. Three distinguishing features are a white patch on the muzzle, webbed hind feet, and large, bright orange-yellow incisors. The nipples of female coypu are high on her flanks, to allow their young to feed while the female is in the water.