Conservation implications of revised genetic structure resulting from new population discovery: the threatened eastern sand darter (Ammocrypta pellucida) in Canada.

Abstract

Human activity can put non-game fishes at higher risk of extinction due to inappropriate management action. Eastern sand darter (Ammocrypta pellucida), a small benthic fish classified as threatened across much of its northern range, inhabits increasingly fragmented sandy habitats and, as a non-game fish, may be easily overlooked in conservation efforts. Here, we use genotype data from nine microsatellite loci and cytochrome oxidase I (COI) sequencing data across its northern native range to re-assess genetic structure and to characterize a newly discovered, geographically disjunct population. Previous microsatellite marker analyses had identified seven distinct population genetic clusters across the region sampled; our analysis showed that the newly discovered population (West Lake, Ontario) exhibits a divergent structure. COI haplotype analysis suggests that a single haplotype recolonized the Great Lakes and surrounding waterbodies after the Wisconsinan glacial period, and subsequent fluctuation in water levels and habitat fragmentation resulted in divergence of genetic clusters. While the novel West Lake population has a common ancestral source with other populations in the broader region, its divergent genetic signature merits its consideration as a separate conservation unit. Our analyses highlight the potential conservation implications of the discovery of new populations, particularly those of at-risk species, even within a region that has been genetically well characterized. This article is protected by copyright. All rights reserved.