Assessing genetic diversity, fine-scale population structure, and demographics in the narrow endemic chittenango ovate amber snail (Novisuccinea chittenangoensis)

We document isolation and characterization of 12 tetra-nucleotide microsatellite DNA markers in the hermaphroditic Chittenango ovate amber snail (Novisuccinea chittenangoensis) endemic to Chittenango Falls in central New York State, USA. The markers displayed a moderate level of allelic diversity (averaging 5.2 alleles/locus) and heterozygosity (averaging 58.6%) in the single extant population. Allelic diversity was sufficient to produce unique multilocus genotypes; no indication of selfing was observed among this cosexual species. Minimal deviations from Hardy-Weinberg equilibrium and no linkage disequilibrium were observed when three collections, representing different rock ledge heights, were analyzed separately. A series of analyses identified weak population differentiation among the ledge collections. Demographic analyses suggested each collection has achieved mutation-drift equilibrium. The microsatellite markers developed for N. chittenangoensis yielded sufficient genetic diversity to: (i) distinguish all individuals and assess the level of selfing; (ii) elucidate fine-scale population structuring; and (iii) provide unique demographic perspectives for recovery efforts.