Genetic structure and effective population size of the most northern population of the Australian River Blackfish, Gadopsis marmoratus (Richardson 1848): Implications for long-term population viability

Authors/Creators

Joel A. Huey, Edith Cowan University
Stephen R. Balcombe
Kathryn M. Real
David Sternberg
Jane M. Hughes

Abstract

Upland freshwater habitats support populations that are especially susceptible to anthropogenic change. Furthermore, their isolation from other suitable habitats, and the fragmented, dendritic structure of headwaters make dispersal an unlikely response to change. We investigated genetic structure and variation in the northernmost population of Gadopsis marmoratus, which is isolated in a tiny area in the headwaters of the Condamine River catchment, in the Murray - Darling Basin, Australia. Strong genetic structure was detected among subpopulations based on microsatellites (F_ST 5 0.173, p < 0.0001) and mitochondrial (mt)DNA (F_ST 5 0.369, p < 0.05). Effective population size was low, ranging between 18.8 and 48.2, depending on the estimation method used. Bayesian clustering revealed 3 genetic clusters, but they were not congruent with drainage patterns, suggesting a complex history of dispersal among headwaters that are isolated by waterfalls. Overall, these results suggest that G. marmoratus is unlikely to disperse into new habitats if local conditions become unsuitable. Low effective population size and genetic diversity also suggest that local adaptation would be unlikely.

Document Type

Journal Article

Date of Publication

2017

Location of the Work

United States

School

School of Science

Copyright

free_to_read

Publisher

University of Chicago Press

Comments

Huey, J. A., Balcombe, S. R., Real, K. M., Sternberg, D., & Hughes, J. M. (2017). Genetic structure and effective population size of the most northern population of the Australian River Blackfish, Gadopsis marmoratus (Richardson 1848): Implications for long-term population viability. Freshwater Science, 36(1), 113-123. https://doi.org/10.1086/690557

Recommended Citation

Huey, J. A., Balcombe, S. R., Real, K. M., Sternberg, D., & Hughes, J. M. (2017). Genetic structure and effective population size of the most northern population of the Australian River Blackfish, Gadopsis marmoratus (Richardson 1848): Implications for long-term population viability. DOI: https://doi.org/10.1086/690557