Geographical Distribution of Mauremys sinensis, Mauremys reevesii, and Their Hybrids in South Korea

The Chinese striped-necked turtle <i>Mauremys sinensis</i>, introduced into South Korea presumably in 2012, is considered an invasive alien species owing to its devastating impact, including hybridization with the native protected species Reeves' turtle <i>M. reevesii</i>. Recently, the presence of <i>M. sinensis</i> has been confirmed throughout the country, and several sympatric areas with <i>M. reevesii</i> have been reported. Thus, field surveys were conducted at 47 sites across <i>M. sinensis</i> and <i>M. reevesii</i> habitats in South Korea to determine the extent of hybridization. Five sympatric sites were confirmed, and hybrid individuals were identified at four sites. Genetic analyses (<i>COI</i> and <i>R35</i>) of two individuals from Jeju Island confirmed maternal <i>M. reevesii</i> and paternal <i>M. sinensis</i> lineages. Hybridization presumably does not occur under natural conditions, and the hybrids likely originated from captive breeding. This study identifies for the first time the habitats of <i>M. sinensis</i> and its hybrids in the wild of South Korea. The management measures proposed in the current study could be of value for the conservation of the native species; however, our study did not include reproductive monitoring, and there is a need for such surveys as well as for systematic management of non-native turtles introduced into South Korea.