Conservation of the Owens Pupfish: Genetic Effects of Multiple Translocations and Extirpations

Abstract

AbstractThe Owens Pupfish Cyprinodon radiosus represents many of the challenges of managing threatened or endangered species in fragmented refuge populations. All six extant populations of the endangered Owens Pupfish were examined to assess how management practices, including serial translocations and founder events, have influenced the genetic diversity of the species and to make recommendations for future management. Four populations were sampled twice with 3–4 years intervening; two additional populations were sampled once. Populations were genotyped at nine microsatellite loci; estimated effective population sizes ranged from 34.2 to 347.8 individuals based on the linkage disequilibrium method and from 10 to 48 using the sibship assignment method. All of the populations were estimated to have undergone severe bottlenecks, and statistically significant pairwise FST values increased during the period between sampling. From this data we infer that the individual refuge populations have differentiated and lost genetic diversity and that without intervention they will continue to do so. For the long‐term persistence of this species, we recommend founding new populations composed of 30–50 founders from each of the extant populations, regularly translocating up to 10 migrants per generation among stable populations, and maximizing habitat area and quality.