Locations of eDNA sampling sites.

Seven gray dots show the site locations with capitalized abbreviations of each name. A green triangle named “Tide Sta.” indicates the location of the tidal observation station. Blue lines illustrate rivers that S. lanceolatus is believed to migrate into. The river and coastline data were provided by the National Land Information Division, Ministry of Land, Infrastructure, Transport and Tourism of Japan, under the CC BY 4.0 license.