coypu n : aquatic South American rodent resembling a small beaver; bred for its fur [syn: nutria, Myocastor coypus]

English

Noun

1. A large, crepuscular, semiaquatic rodent (Myocastor coypus) resembling a large rat, having bright orange-yellow incisors, native to South America, Europe, Asia and North America, valued for its fur in eastern Europe and central Asia and considered a pest elsewhere.

Synonyms

• nutria (especially North America)

Translations

• Dutch: beverrat
• German: Biberatte , Nutria, Sumpfbiber, Schweifbiber, Schweifratte, Coypu
• Korean: 뉴트리아 (nyuteuria)
• Russian: нутрия /nútrija/

The coypu, or nutria (Myocastor coypus) is a large, herbivorous, semiaquatic rodent and the only member of the family Myocastoridae. Originally native to temperate South America, it has since been introduced to North America, Europe, Asia and Africa, primarily by fur ranchers. Although it is still valued for its fur in some regions, its destructive feeding and burrowing behaviors make this invasive species a pest throughout most of its range.

There are two commonly-used names in the English language for Myocastor coypus. The name nutria (or local derivatives such as "nutria- or nutra- rat") is generally used in North America and Asia; however, in Spanish-speaking countries, the word nutria refers to the otter. To avoid this ambiguity, the name coypu (derived from the Mapudungun word kóypu) is used in Latin America and Europe. In France, the coypu is known as a ragondin. In Dutch it is known as beverrat (beaver rat).

Taxonomy

The coypu was first described by Juan Ignacio Molina in 1782 as Mus coypus, a member of the mouseor (tervanis) genus. The genus Myocastor, assigned in 1792 by Robert Kerr, is derived from the Greek mys and kastor, or "mouse-beaver". Geoffroy, independently of Kerr, named the species Myopotamus coypus, and it is occasionally referred to by this name.

Four subspecies are generally recognized: In the Chesapeake Bay region in Maryland, where they were introduced in the 1940s, coypu are believed to have destroyed 7,000 to 8,000 acres (32 km²) of marshland in the Blackwater National Wildlife Refuge. In response, by 2003, a multi-million dollar eradication program was underway.

Coypu were also introduced to East Anglia, again for fur, in 1929; many escaped and damaged the drainage works, and a concerted program by MAFF eradicated them by 1989. Coypu meat is lean and low in cholesterol. While there have been many attempts to establish markets for coypu meat, all documented cases have generally been unsuccessful. Unscrupulous entrepreneurs have promoted coypu and coypu farms for their value as "meat", "fur", or "aquatic weed control". In recent years they have done so in countries such as the United States, China, Taiwan and Thailand. In every documented case the entrepreneurs sell coypu "breeding stock" at very high prices. Would-be coypu farmers find that the markets for their products disappear after the promoter has dropped out of the picture.

In the former Soviet republics of Central Asia, specifically Kyrgyzstan and Uzbekistan, Nutria (Russian and local languages Нутриа) are farmed on private plots and sold in local markets as a poor man's meat.

In addition to direct environmental damage, coypu are the host for a nematode parasite (Strongyloides myopotami) that can infect the skin of humans. When this happens the condition is called "nutria itch."

Distribution

The distribution of coypu tends to expand and contract with successive cold or mild winters. During cold winters, coypu often suffer frostbite on their tails leading to infection or death. As a result, populations of coypu often contract and even become locally or regionally extinct (as in the Scandinavian countries during the 1980s). During mild winters, their ranges tend to expand northward.

References

• Sandro Bertolino, Aurelio Perrone, and Laura Gola "Effectiveness of coypu control in small Italian wetland areas" Wildlife Society Bulletin Volume 33, Issue 2 (June 2005) pp. 714–72.
• Carter, Jacoby and Billy P. Leonard: "A Review of the Literature on the Worldwide Distribution, Spread of, and Efforts to Eradicate the Coypu (Myocastor coypus)" Wildlife Society Bulletin, Vol. 30, No. 1 (Spring, 2002), pp. 162-175.
• Carter, J., A.L. Foote, and L.A. Johnson-Randall. 1999. Modeling the effects of nutria (Myocastor coypus) on wetland loss. Wetlands 19(1):209-219
• Lauren E. Nolfo-Clements: Seasonal variations in habitat availability, habitat selection, and movement patterns of Myocastor coypus on a subtropical freshwater floating marsh. (Dissertation) Tulane University. New Orleans. 2006. ISBN 0542609169

Notes

External links

• Mammals of Texas - Nutria
• History, distribution and spread of coypu introductions worldwide; efforts to eradicate with links to other nutria sites
• Louisiana Department of Wildlife and Fisheries' coypu website
• National Trappers - Nutria
• Nutria Recipes developed for a nutria control program
• The Effect of Nutria on Marsh Loss in the Lower Eastern Shore of Maryland undated USGS report