Environmental DNA analysis provides an overview of distribution patterns of two dojo loach species within the Naka-ikemi Wetland, Fukui Prefecture, Japan

In the Naka-ikemi Wetland, a cryptic species of the dojo loach, Misgurnus sp. Type I (called Type I loach herein), inhabits along with the common nominal species, Misgurnus anguillicaudatus (called Type II loach herein). In this study, the distribution patterns of two loaches were investigated by environmental DNA (eDNA) analysis and previously suggested habitat segregation between two sympatric loaches was discussed. Type I loach tended to have a limited distribution, mainly inhabiting the northern part of the wetland; Type II loach tended to be widely distributed across the central to southern parts of the wetland. Both loaches occurred sympatrically in some areas throughout the sampling periods, indicating that they did not completely segregate their habitats.