Genetic Diversity and Population Structure of Nutria (Myocastor coypus) in South Korea

SIMPLE SUMMARY: Nutrias (Myocastor coypus) are large semiaquatic rodents native to subtropical and temperate South America. Nutrias have been introduced on all continents, except Oceania and Antarctica, and have become invasive in many countries. This study carried out a survey of nutrias in South Korea under the Nutria Eradication Project from January 2013 to August 2015. Out of 1509 habitat traces, 1497 tracks were observed in the Nakdong River basin. Based on the ecological field data, we identified concentrated areas of nutria populations. Tissue samples were collected from captured nutria for genetic analysis. According to the microsatellite marker analysis, the estimated genetic diversity of the nutria populations was low, which suggests that nutrias in South Korea originate from a single population. ABSTRACT: The nutria (Myocastor coypus) is an invasive alien species that have had major adverse effects on biodiversity and the agricultural economy in wetland habitats. Since 2014, the Ministry of Environment in South Korea has been carrying out the Nutria Eradication Project, and we investigated nutria distribution and genetic diversity of nutria populations in South Korea. We estimated that 99.2% of nutria habitats are in the mid-lower Nakdong River regions. To further analyze the genetic diversity in eight major nutria populations, we performed a genetic analysis using microsatellite markers. Genetic diversity levels of the eight nutria populations in South Korea were relatively lower than those in other countries. The probability of migration direction among nutria populations was predicted from genetic distance analysis. Genetic structure analysis showed little difference among the nutria populations in South Korea. These results suggest that nutrias in South Korea originated from a single population. Our results provide important data for establishing management strategies for the successful eradication of nutria populations in South Korea, as well as in other countries with alien invasive species.