Characterization of tri and tetra-nucleotide microsatellite loci for the freshwater snails Promenetus exacuous (Planorbidae) and Valvata tricarinata (Valvatidae) and their utility in population genetic studies

OBJECTIVE: Promenetus exacuous and Valvata tricarinata are freshwater snail species with widespread distributions throughout North America. Information regarding their genetic diversity and population connectivity are currently lacking. We utilized next generation sequencing to develop the first microsatellites for each species to investigate genetic diversity within and differentiation among populations. RESULTS: Sixteen and seventeen microsatellite loci were developed for P. exacuous and V. tricarinata, respectively, and tested in a total of 43 P. exacuous and 48 V. tricarinata from two lakes approximately 183 km apart in New York State, USA. Fifteen P. exacuous loci were polymorphic in at least one lake and possessed 1–23 alleles and observed heterozygosities of 0.00–0.96 within individual lakes. Seventeen polymorphic V. tricarinata loci possessed 2–19 alleles and observed heterozygosities of 0.04–0.96 within lakes. Bayesian clustering using 12 loci for each species identified two distinct genetic populations, reflecting the two lakes. High assignment scores for individual snails to the lakes they were collected from supported strong population structure with minimal admixture at the scale of this study. These loci will be useful for investigating the genetic diversity and population structure of these species and indicate genetic differentiation may be common among their populations.