Genetic diversity and divergence in the fountain darter (Etheostoma fonticola): implications for conservation of an endangered species
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The endangered fountain darter Etheostoma fonticola is found only in the Comal and San Marcos rivers in the Guadalupe River basin in central Texas, USA. Comal River fountain darters were believed to be extirpated following a severe drought in the 1950s and were reintroduced in the early 1970s using 457 darters from the San Marcos River. In this study we used 23 microsatellite loci to describe and evaluate the genetic diversity, population structure and effective population size (N e) of fountain darters. We also evaluated the genetic effect of the Comal River reintroduction and the influence of low-head dams (dams) on dispersal in both rivers. Bayesian analysis of individual genotypes and Analysis of Molecular Variation supported two distinct populations concordant with the two rivers. Estimates of N e were much smaller (<10 %) than census size (N c) in both rivers but did not indicate the populations are at risk of an immediate and rapid loss of genetic diversity. Coalescent-based estimates of the genetically effective number of founders (Nf) for the Comal River averaged about 49 darters and, together with the indices of genetic diversity and the bottleneck test (heterozygosity excess) results, were consistent with a founder event following the reintroduction in the Comal River. Finally, our results regarding the influence of dams on fountain darter dispersal were equivocal and did not support a conclusion. We recommend this issue be examined further as part of the fountain darter recovery program.
KeywordsFountain darter Genetic diversity Endangered species Reintroduction Effective founder number
This project was partially funded by the Edwards Aquifer Recovery Implementation Program. Additional thanks to anonymous for valuable suggestions regarding the composition of this manuscript. The findings and conclusions in this article are those of the author(s) and do not necessarily represent the views of the U.S. Fish and Wildlife Service.
- Brune GM (2002) Springs of Texas. Texas A&M University Press, College StationGoogle Scholar
- [ESA] Endangered Species Act of 1973, Pub. L. No. 93- 205, 87 Stat. 884 (Dec. 28, 1973)Google Scholar
- Excoffier L, Laval G, Schneider S (2005) Arlequin ver. 3.0: An integrated software package for population genetics data analysis. Evol Bioinform Online 1:47–50Google Scholar
- Goudet J (2001) FSTAT, a program to estimate and test gene diversities and fixation indices (version 2.9.3). http://www.unil.ch/izea/softwares/fstat.html
- Kern EW, Hotchkiss RH, Ames DP (2015) Introducing a low-head dam fatality database and internet information portal. JAWRA 51(5):1453–1459Google Scholar
- Linam GW, Mayes KB, Saunders KS (1993) Habitat utilization and population size estimate of fountain darters Etheostoma fonticola in the Comal River, Texas. Texas J Sci 45:341–348Google Scholar
- Rice WR (1989) Analyzing tables of statistical tests. Evol 43:223–225Google Scholar
- Stockwell CA, Vinyard GL (2000) Life history variation in recently established populations of western mosquitofish (Gambusia affinis). West N Am Nat 60:273–280Google Scholar
- US Fish and Wildlife Service (1996) San Marcos and Comal springs and associated aquatic ecosystems (Revised) recovery plan. U.S. Fish and Wildlife Service, Albuquerque, NM. http://ecos.fws.gov/docs/recovery_plan/960214.pdf. Accessed 17 Dec 2015