Conservation Genetics

, Volume 13, Issue 5, pp 1317–1328 | Cite as

Genetic analysis suggests high conservation value of peripheral populations of Chihuahau chub (Gila nigrescens)

  • Megan Osborne
  • Alana Sharp
  • Jerry Monzingo
  • David L. Propst
  • Thomas F. Turner
Research Article


Genetic drift is expected to be the predominant evolutionary force in small, fragmented peripheral populations, which can lead to divergent allele frequencies and lowered diversity compared to the core population. Peripheral populations are not considered a high priority for conservation for this reason. However, peripheral populations may possess unique genetic variability not found elsewhere in the species’ range, and may be especially important if core populations are at extirpation risk. Here, we characterized levels and patterns of genetic diversity at microsatellites and mtDNA for the peripheral populations of Chihuahua chub in New Mexico, and compared these results to populations in Mexico including a new locality in the Rio Yaqui basin. All populations of Chihuahua chub in New Mexico were genetically depauperate as expected due to their small and peripheral status, and harbored distinct variation compared to those in Mexico. Allele and haplotype frequencies were divergent between New Mexican and Mexican populations, and mitochondrial haplotypes were not shared between them. All New Mexican populations were significantly divergent from one another suggesting little genetic exchange. New Mexican populations also exhibited relatively small genetic effective size. Chihuahua chub in New Mexico thus represent a unique component of the species’ evolutionary legacy and hence suggests high conservation value of this peripheral population. Conservation value of this population is bolstered by the fact that Chihuahua chub has more legal protection than counterparts in Mexico.


Core Population Private Allele Captive Population Mexican Population Peripheral Population 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



Sincere thanks are extended to Angela James (U.S. Fish and Wildlife Service) for sample collection. We are also grateful to Thomas E. Dowling and Richard L. Mayden who provided samples from Mexico, and to Paul Moreno who granted permission to sample and retain specimens from his property at Moreno Spring. Likewise, The Nature Conservancy and the New Mexico Department of Game and Fish granted permission to sample adjacent to their properties in the Mimbres River. Samples were also provided by Dexter National Fish Hatchery and Technology Center. We are extremely grateful to Alejandro Garza (ProNatura, MX) and Tyler Pilger for assistance in producing maps for this paper. Krista Heideman provided information about microsatellite primer optimization, Thien Le and Samantha Sanchez provided laboratory assistance. Funding was provided by the N.M. Department of Game and Fish Share with Wildlife Program (to MJO and TFT). New Mexico samples were collected under NM Game and Fish permit numbers: 3015 and 1776. IACUC protocol number 10-100492-MCC.


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Copyright information

© Springer Science+Business Media B.V. 2012

Authors and Affiliations

  • Megan Osborne
    • 1
  • Alana Sharp
    • 1
  • Jerry Monzingo
    • 2
  • David L. Propst
    • 1
  • Thomas F. Turner
    • 1
  1. 1.Department of Biology and Museum of Southwestern BiologyUniversity of New MexicoAlbuquerqueUSA
  2. 2.USDA Forest ServiceSilver CityUSA

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