CoypuFossil range: Late Pliocene - Recent |
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Scientific classification |
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Binomial name |
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Myocastor coypus |
The coypu or nutria
(Myocastor coypus) (or in Louisianan vernacular, "nuture rat")
is a large, crepuscular, semiaquatic rodent native to South America, but now
also present in Europe, Asia, and North America. In most regions, the coypu is
considered a pest. However, in eastern Europe and Central Asia, it is still
valued for its fur. It is the only species in the genus Myocastor
and is sometimes given its own family: Myocastoridae. The coypu, an
herbivore, has been introduced from South America to every continent except
Australia and Antarctica. Africa is the only continent where the introduced
coypu never became fully established. The animal is adapted to subtropical to
mild temperate climates.
There are two common names
used in the English language for Myocastor coypus. Coypus originated
from the Amerindian Mapudungun language word coypu or kóypu and
was adopted by American Spanish as Coipo is generally used in Europe and
Latin America. This avoids confusion with the term "nutria," which is
Spanish for carnivores commonly called otters (Lutra sp.) in British and
American English. In North America and Asia, the term nutria is the more
commonly used one for Myocastor coypus.
The coypu somewhat
resembles a very large rat in appearance. Adults are typically 5–9 kg (10-20 lbs)
in weight, and 40–60 cm (15-24 inches) in body length, with a 30–45 cm (12-18
inches) tail. They can also be identified by their bright orange-yellow incisor
teeth (unlike rats, which have brownish yellow incisors). The nipples of female
coypu are on her back. This allows their young to feed while the female is in
the water.
Coypu can also be mistaken
for another widely dispersed semi-aquatic rodent that occupies the same wetland
habitats, the muskrat. However, the muskrat is smaller, more tolerant of cold
climates, and has a dorso/ventrally flattened tail that it uses to assist in
swimming, whereas the tail of a coypu is round.
There are several
subspecies of coypu in their native range which includes parts of Argentina,
Bolivia, Brazil, Chile, Paraguay and Uruguay. While as many as six different
subspecies have been named generally there are only four recognized. They are: Myocastor
coypus coypus, M. coypus bonarieusis, M. coypus melanups, and
M. coypus santacruzae. Most literature indicates the coypu subspecies
introduced around the world was M. coypus bonariensis. This subspecies
is from the more northern (subtropical) part of their range.
Local extinction in their
native range due to overharvest led to the development of coypu fur farms in
the late 1800s and early 1900s. The first farms were in Argentina and then
later in Europe, North America, and Asia. In general, these farms have
generally not been successful long term investments and farmed coypu often are
released or escape as operations become unprofitable.
As demand for coypu fur
declined, coypu have since become pests in many areas, destroying aquatic
vegetation, irrigation systems, eroding river banks and displacing native
animals. For example, coypu were introduced to Louisiana in the 1930s for fur,
and nutria damage in Louisiana is so severe in 2005 that a bounty program is in
effect to aid in controlling the animal. In the Chesapeake Bay region in
Maryland, where they were introduced in the 1940's, coypu are believed to have
destroyed 7,000 to 8,000 acres of marshland in the Blackwater National Wildlife
Refuge. In response, by 2003, a multi-million dollar eradication program was
underway. [1]
Coypu were also introduced
to East Anglia, again for fur, in 1929; many escaped and damaged the drainage
works, and a concerted programme 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. [citation
needed]
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."
Wikipedia
http://en.wikipedia.org/w/index.php?title=Coypu&action=history
http://www.gnu.org/copyleft/fdl.html