Myocastor coypus (Molina, 1782) —Coypu, Nutria

Mus coypus Molina, 1782 p.287; Type locality- Rio Maipo, Santiago, Chile.

Myocastor coypus: Han, 2004c p.141.

Range: Despite few occurrences at several sites in South Korea from Jeju Island to the Han River (Jo et al. 2017a), the distribution of this semi-aquatic, invasive species is limited to the Nakdong River system with the Upo Wetlands in Gyeongsangnam Province (Jo et al. 2017a; Fig. 115). However, transient individuals often disperse north and west of Gyeongsangnam Province.

Remarks: The first importation occurred in 1985 for fur farming, with 470 coypu farms housing about 150,000 animals (Jo et al. 2017a). Due to a decline in the market demand for fur and failure of the development of a market for the meat, most farms closed for business with some farmers releasing the animals into the environment, the coypu became an invasive species by 2001 (Jo et al. 2017a). Even with the decrease in fur demand, some coypu farms have continued to import nutrias, further reinforcing risks of release into the wild. The source populations for these imported rodents are unknown because no data exist for animals on farms or feral animals in the environment. Microsatellite analysis of nutria in the Upo Wetlands showed considerable genetic diversity and indicated, at least, two source populations (Jung & Jo 2012). The Ministry of Environment and local governments nearby the Nacdong River system have actively eradicated coypus by bounty money (about $30 USD) or hiring trappers (Jo et al. 2017a).