Establishment of environmental DNA method for detecting invasive African-clawed frogs in Japan

African-clawed frogs (Xenopus laevis) are invasive to many aquatic ecosystems across the globe worldwide. For an accurate and efficient determination of their distribution, the use of environmental DNA (eDNA) could facilitate broad surveys rooted simply in the collection of water samples from inhabited water bodies. Therefore, in this study, using species-specific primers, an eDNA method was developed to evaluate the distribution of African-clawed frogs in Japan. This newly developed method was tested in ponds in Wakayama Prefecture, Japan, and compared with conventional cage trap surveys. Overall, we successfully developed the abovementioned eDNA method and it was shown to be as effective as the conventional capture-related technique.