Risk of extinction cascades from freshwater mussels to a bitterling fish
Bitterling fishes (Subfamily: Acheilognathinae) spawn in the gills of living freshwater mussels obligately depending on the mussels for reproduction. On the Matsuyama Plain, Japan, populations of unionid mussels--Pronodularia japanensis, Nodularia douglasiae, and Sinanodonta lauta--have decreased rapidly over the past 30 years. Simultaneously, the population of a native bitterling fish, Tanakia lanceolata, which depends on the three unionids as a breeding substrate, has decreased. Furthermore, a congeneric bitterling, Tanakia limbata, has been artificially introduced, and hybridisation and genetic introgression occur between them. Here, we surveyed the reproduction and occurrence of hybridisation between native and invasive species ...










