| Invasion information | 
| Range in Japan | Tokyo, Chiba, Saitama Prefs. |   | 
| Origin | N America | 
| Date | Imported before W.W.II. The first record of naturalization in Japan is in 1947. | 
| Route | Deliberate: Bred for fur before the W. W. II, and released after the War. | 
| Impact | Actually: Predation on aquatic plants such as lotus. In Europe, destruction of bank and dam by nest building. Native organism(s) affected: Aquatic plants.
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| Regulation in Japan | Import, transport and keeping are legally restricted in Japan. | 
| Introduced range in other countries | C & N Europe, Ukraine, Russia, Mongolia, China, and NE Korea. |