Conservation Genetics

, Volume 13, Issue 2, pp 349–358 | Cite as

Dramatic shifts in the gene pool of a managed population of an endangered species may be exacerbated by high genetic load

  • Andrew P. MartinEmail author
  • Anthony A. Echelle
  • Gerard Zegers
  • Sherri Baker
  • Connie L. Keeler-Foster
Research Article


The Devils Hole pupfish, Cyprinodon diabolis, is restricted to a small habitat in southwestern Nevada. In 1972 the species was federally listed as an endangered species. Management efforts to mitigate extinction risks have been plagued by the inability to propagate the species in aquaria—anomalous for the genus—and repeated failure of propagation attempts in large, outdoor, artificial pools designed to mimic natural conditions in Devils Hole. These difficulties indicate that the species either has niche requirements that are not adequately recreated under artificial conditions or that it harbors a relatively large genetic load of deleterious mutations that compromises propagation. We used variation at 12 microsatellite loci to evaluate the results of natural, uncontrolled hybridization involving a population of C. diabolis inhabiting an artificial pool and invaders from a nearby population of the closely related C. nevadensis. The results suggest that following invasion of the pool by three C. nevadensis individuals, the gene pool underwent a rapid shift from pure C. diabolis to one comprised mostly of C. nevadensis alleles. Alleles diagnostic for C. nevadensis increased from about 0.03 to an average of 0.76 across four diagnostic loci over the course of 8 years or less. Although we cannot exclude explanations based on adaptation to Devils Hole, genetic drift, or demographic variability, these results and various other aspects of the biology of C. diabolis are best explained by the genetic load hypothesis. The work suggest avenues for future experimental work to evaluate these possibilities directly and provide an explanation for why some previous propagation efforts designed to mitigate extinction risk have failed.


Small populations Genetic load Endangered species Pupfish Microsatellites 



Many individuals provided assistance, samples and funding to complete this project. Cynthia Martinez, Nevada Ecological Services Field Office of the United States Fish and Wildlife Service (USFWS) secured funding through the Directors’ Priority Projects and Manuel Ulibarri, Dexter National Fish Hatchery and Technology Center (USFWS) provided project oversight. Bruce Turner provided some tissue samples and Wade Wilson and Teresa Lewis provided internal reviews. Others that have contributed time and effort to this project include Cristi Baldino, Sharon McKelvey, Shawn Goodchild, Darrick Weissenfluh, Jim Heinrich, Brian Hobbs, and Jennifer Wilcox. The findings and conclusions in this article are those of the authors and do not necessarily represent the views of the U.S. Fish and Wildlife Service.


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Copyright information

© Springer Science+Business Media B.V. 2011

Authors and Affiliations

  • Andrew P. Martin
    • 1
    Email author
  • Anthony A. Echelle
    • 2
  • Gerard Zegers
    • 3
  • Sherri Baker
    • 4
  • Connie L. Keeler-Foster
    • 4
  1. 1.Department of Ecology and Evolutionary BiologyUniversity of ColoradoBoulderUSA
  2. 2.Zoology DepartmentOklahoma State UniversityStillwaterUSA
  3. 3.Department of BiologyUniversity of MaineMachiasUSA
  4. 4.Molecular Ecology ProgramDexter NFHTCDexterUSA

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