Chimarrogale platycephala (Japanese water shrew) is an endangered, semi-aquatic mammal species in Japan, and understanding the C. platycephala habitat is vital for conservation planning. However, the species is difficult to locate using conventional methods, like visual observations and camera/video traps, due to its small size, nocturnal behavior, and low population densities in semi-aquatic environments. Environmental DNA (eDNA) analysis has been used to survey distributions of macro-organisms, with the advantage of non-invasiveness, high sensitivity, and cost-effectiveness. In this study, we analyzed the eDNA in flowing water from possible C. platycephala habitats, using a metabarcoding approach that allows simultaneous multi-species detection. The eDNA of this species was detected at 2 of the 16 study sites. Based on eDNA screening data, camera trap surveys confirmed the presence of shrews at both locations. This study successfully discovered a previously unknown habitat of an endangered semi-aquatic mammal, using eDNA metabarcoding and camera traps. Wide ranging use of eDNA surveys will facilitate detection and appropriate conservation of C. platycephala, and can be applied to other critically endangered semi-aquatic mammals.

Chimarrogale platycephala（日本水sh）是日本一种濒临灭绝的半水生哺乳动物物种，因此了解C. platycephala栖息地对于保护规划至关重要。但是，由于其尺寸小，夜间活动和在半水生环境中的低种群密度，很难使用常规方法（如目视观察和照相机/视频陷阱）来定位该物种。环境DNA（eDNA）分析已被用于调查宏观生物的分布，其优点是无创性，高灵敏度和成本效益。在这项研究中，我们分析了在的eDNA流水从可能的C. platycephala栖息地，使用允许同时进行多种物种检测的元条形码方法。在16个研究地点中的2个检测到该物种的eDNA。根据eDNA筛选数据，相机陷阱调查确认了两个地点都存在sh。这项研究使用eDNA元条形码和相机陷阱成功地发现了濒临灭绝的半水生哺乳动物的先前未知的栖息地。广泛的使用的eDNA调查将有利于检测和适当的养护C. platycephala，并且可以被应用到其他极危半水生哺乳动物。