Population structure, multiple paternity, and long-distance transport of spermatozoa in the freshwater musselLampsilis cardium(Bivalvia:Unionidae)

Freshwater mussels (Bivalvia:Unionidae) are among the most imperiled organisms in North America. Information on the spatial scale of reproduction and population connectivity will better enable mussel conservation programs to sustain long-term population viability, particularly restocking and recovery programs. Here we used genetic methods to characterize population structure, dispersal potential, and reproductive strategies in the freshwater mussel Lampsilis cardium from Twin Creek and Big Darby Creek (Ohio, USA). We genotyped adults and individual glochidia at 12 microsatellite loci to assess local population structure relative to within-population patterns of relatedness and parentage. Local populations within watersheds were weakly structured, and within-population estimates of relatedness identified probable full- and half-siblings several kilometers apart. Parent–offspring comparisons provided evidence of multiple paternity in single broods and identified the likely father of 3 glochidia from...