Genetic diversity maintained in comparison of captive-propagated and wild populations of Lampsilis fasciola and Ptychobranchus fasciolaris (Bivalvia: Unionidae)
We compared the genetic diversity and structure between wild and captive-propagated freshwater mussels at risk in Canada, Lampsilis fasciola (Wavy-rayed Lampmussel, WRL) and Ptychobranchus fasciolaris (Kidneyshell, KS), using microsatellite generated genotypes. No significant differences were detected between wild and propagated WRL (from 12 mothers) or KS (from 7 mothers) based on genetic diversity metrics using Kruskal-Wallis tests. Effective population size (Ne) was estimated and there was considerable overlap in the estimated Ne between wild and captive populations of both species. Pairwise FST and Dest values among wild WRL, hatchery-raised WRL juveniles, and across different time periods (2008 to 2018) were generally low (FST = 0.007-0.043, Dest = 0.005-0.282). Pairwise FST and Dest for KS were not significant and low (0.012, 0.017). When comparing captive-reared offspring with the wild population, STRUCTURE analysis revealed strong support for a single genetic population. With at least 7 females contributing to brood stock, genetic diversity was maintained. Further research is needed to assess the male contribution to each glochidial brood, and the variability of genetic diversity in individual glochidial broods.