Cryptic invasion of Northern Leopard Frogs (Rana pipiens) across phylogeographic boundaries and a dilemma for conservation of a declining amphibian
- 493 Downloads
Anthropogenic introduction of species is a major contributor to loss of biodiversity. Translocations within the range of a species are less frequently recognized, but have the potential for negative effects as well. Genetic mixing may lead to loss of local adaptations or further decline through outbreeding depression. These cryptic invasions may be quite difficult to recognize, but genetic tools can be used to recognize and monitor such intraspecific introductions. Conversely, translocations within species can be an important conservation tool to reduce inbreeding depression and replace lost genetic diversity. Thus, cryptic invasions can be either an aid or a hindrance to conservation efforts. We tested for the presence of non-native genotypes and assessed the extent and nature of introgression in populations of Northern Leopard Frog (Rana pipiens) in the southwestern US, where populations have declined to a few remnant populations. The most abundant and diverse complex of populations in the region contained a mitochondrial haplotype that was not native to the western US, probably resulting from the introduction of released pets, laboratory animals, or release during fish stocking. These non-native haplotypes were well integrated into a large complex of ponds and lakes, contributing to high genetic diversity in this area. Logistically, the geographic extent of non-native genetic influence within this population precludes eliminating or controlling the non-native component of this population. We recommend assessing the progress and fate of the introgression over time—along with population fitness parameters—to determine whether this introduction is beneficial or detrimental to population persistence. Meanwhile, translocations from nearby locations with similar environmental conditions have the best prospects for avoiding problems with outbreeding depression in other declining populations and will also most effectively preserve regional genetic diversity.
KeywordsCryptic invasion Population genetics Lithobates pipiens Northern Leopard Frog Introgression
Funding for this work was provided by the Heritage Fund Program of the Arizona Game and Fish Department. A Willard L. Eccles Graduate Fellowship from the Utah State University College of Science provided partial support for Ryan O’Donnell. Lisa Gelczis, Caleb Loughran, A. J. Monatesti, Dan Groebner, Diana Kimberling, Susan MacVean, and Oliver Hyman collected genetic samples. Susan MacVean of the Arizona Game and Fish Department provided assistance, advice, and insights. Jer Pin Chong, Catherine M. Culumber, and Jay Baker contributed to laboratory work. Tara Fulton and Greg Wilson of the University of Alberta provided access to primers and unpublished data. Preliminary portions of this manuscript were published as part of a peer-reviewed US Geological Survey Open-File Report, number 2011-1186.
- Cornuet JM, Luikart G (1997) Description and power analysis of two tests for detecting recent population bottlenecks from allele frequency data. Genetics 144:2001–2014Google Scholar
- Drost CA, O’Donnell RP, Mock KE, Theimer TC (2011) Population status and population genetics of Northern Leopard Frogs in Arizona: US Geological Survey Open-File Report 2011-1186. http://pubs.usgs.gov/of/2011/1186/
- Goudet J (1995) FSTAT (version 1.2): a computer program to calculate F-statistics. J Hered 86:485–486Google Scholar
- Green DE (2001) Toe-clipping of frogs and toads. Standard operating procedure. United States Geological Survey, National Wildlife Health Center. http://www.nwhc.usgs.gov/publications/amphibian_research_procedures/toe_clipping.jsp. Accessed 27 Aug 2016
- Holsbeek G, Mergeay J, Hotz H, Plötner J, Volckaert FAM, De Meester L (2008) A cryptic invasion within an invasion and widespread introgression in the European water frog complex: consequences of uncontrolled commercial trade and weak international legislation. Mol Ecol 17:5023–5035CrossRefPubMedGoogle Scholar
- Moriarty ME (2009) Endangered and threatened wildlife and plants; 90-day finding on a petition to list the Northern Leopard Frog (Lithobates [=Rana] pipiens) in the western United States as threatened. Fed Regist 74:31389–31401Google Scholar
- Parris MJ (2001) Hybridization in leopard frogs (Rana pipiens complex): variation in interspecific hybrid larval fitness components along a natural contact zone. Evol Ecol Res 3:91–105Google Scholar
- Raymond M, Rousset F (1995) GENEPOP (version 1.2): population genetics software for exact tests and ecumenicism. J Hered 86:248–249Google Scholar
- Sredl MJ (1998) Arizona leopard frogs: balanced on the brink? In: Mac MJ, Opler PA, Puckett Hacker CE, Doran PD (eds) Status and trends of the nation’s biological resources. US Department of the Interior, US Geological Survey, Biological Resources Division, Washington, pp 573–574Google Scholar
- Tennessen JA, Woodhams DC, Chaurand P, Reinert LK, Billheimer D, Shyr Y, Caprioli RM, Blouin MS, Rollins-Smith LA (2009) Variations in the expressed antimicrobial peptide repertoire of Northern Leopard Frog (Rana pipiens) populations suggest intraspecies differences in resistance to pathogens. Dev Comp Immunol 33:1247–1257CrossRefPubMedPubMedCentralGoogle Scholar
- Wier BS (1996) Genetic data analysis II: methods for discrete population genetic data. Sinauer Associates Inc, SunderlandGoogle Scholar