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Myocastor coypus

Basic information
Scientific name Myocastor coypus

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Common names Nutria
Higher taxon Echimyidae, Rodentia, Mammalia
Natural range Central to southern part of South America.
Habitat Lake or pond, stream, swamp.
Invasion information
Range in Japan Established in Gifu, Shizuoka, Aichi, Mie, Kyoto, Osaka, Hyogo, Okayama, Tottori, Hiroshima, Shimane, Yamaguchi and Kagawa Prefs.
There are several records of temporary observation or past establishment in several other regions (some of those might be misidentification of musk rat or mink).
Range in Japan
Origin Import of 150 nutrias in 1939 was from France.
Date The first introduction was late Maiji Era (around 1900s). In 1939, 150 nutrias were imported and farmed for military and consumer use in Kanto District to western Japan. Mass release and escape may occur just after W.W.II and after fur vogue in 1950s.
Route Deliberate: Release and escape of cultivated nutria for fur production in the W.W.II period. This species have also been introduced in other countries for fur production, because this species has good fur as an adaptation to semiaquatic habitat.
In other countries, this species is sometimes released for control of aquatic and waterfront weeds or as a sports hunting animal.
Impact Actually: Damage on aquatic plants. Destruction of bank, rice field walk, and water reservior by burrowing. Damage on agricultre.
Native organism(s) affected: Aquatic plants, crops (various crops such as rice, fruits, vegetables).
Regulation in Japan Import, transport and keeping are prohibited in Japan by the Invasive Alien Species Act.
Introduced range in other countries Azerbaijan, Georgia, Israel, Jordan, Kazakhstan, Tajikistan, Turkey, Turkmenistan, wide area in Europe, Kenya, wide are in USA, Canada, northern Mexico, etc.
Reference Notes
  • Abe (ed) (1994) A Guide to Mammals of Japan. Tokai Univ. Press, Hatano (in Jpn)
  • DECO (ed) (2006) Dictionary of Alien Species. Tokyo-Shoseki, Tokyo (in Jpn)
  • Ecol Soc Jpn (ed) (2002) Handbook of Alien Species in Japan. Chijinshokan, Tokyo (in Jpn)
  • ISSG. Global Invasive Species Database (GISD) (Accessed on 2012-6-29)
  • Izawa et al. (eds) (1996) The Encyclopedia of Animals in Japan 2 Mammals II. Heibonsha, Tokyo (in Jpn)
  • JWRC (ed) (2008) A Photographic Guide to the Invasive Alien Species in Japan. Heibonsha, Tokyo (in Jpn)
  • Ministry of the Environment, Japan. The Invasive Alien Species Act (Accessed on 2012-6-29)
  • Ohdachi et al. (eds) (2009) The Wild Mammals of Japan. Shokado, Kyoto.
  • Yamada et al. (eds) (2011) Invasive Alien Mammals in japan: Biology of Control Strategy and Conservation. Univ. Tokyo Press (in Jpn)
  • Kaneko & Kawaguchi (2009) Collecting or observation of the nutria (Myocaster coypus) on Honjima, Teshima, Oteshima, Shyodoshima and Teshima (Marugame City, or Shyozu-gun, Kagawa Prefecture), Seto Inland Sea, Japan. Kagawa Seibutsu. 36, 9-18 (in Jpn with English abst)
  • etc.
100 of the World's Worst Invasive Alien Species, 100 of the Japan's Worst Invasive Alien Species