From Korean to northeast Asian endemicity: on the occurrence of Pelophylax chosenicus along the Eastern Coastal Yellow Sea
Abstract
Understanding the distribution of species is a primary requirement to understand their behaviour, conservation, and phylogeography. Over the last decades, the number of species described on the Korean Peninsula has significantly increased, but surveys around the boundaries of the Peninsula are still needed to refine the range of these species. Further surveys, supported by ecological niche models, are especially needed in areas where the environment is similar and connected. We conducted surveys in the continuous landscapes of the Republic of Korea, the Democratic People’s Republic of Korea, and the People’s Republic of China to determine the distribution of the gold-spotted pond frog, Pelophylax chosenicus (Okada, 1931). The surveys were conducted between 2015 and 2021 through the use of visual and call encounters. We supported our surveys with molecular analyses by sequencing the mitochondrial 16S rRNA, 12S rRNA, and Cytb gene fragments to confirm the species identity of the northernmost population in China. As a result, we found the species to be widespread in low-elevation wetlands along the eastern coast of the Yellow Sea, with two isolated populations in the southeast of the Korean Peninsula, and the northernmost population in the vicinity of Dandong in the People’s Republic of China. We then determined the importance of landscape types for the species, especially rice paddies, and used ecological niche models to define suitable habitats across the region. As this species is listed as threatened in the Republic of Korea, knowing its exact distribution will be important for conservation practices.