Conservation implications of distinct genetic structuring in the endangered freshwater fish Nannoperca oxleyana (Percichthyidae)
James T. Knight A B D , Catherine J. Nock C , Martin S. Elphinstone C and Peter R. Baverstock CA NSW Department of Primary Industries, Locked Bag 1, Nelson Bay, NSW 2315, Australia.
B School of Environmental Science and Management, Southern Cross University, Lismore, NSW 2480, Australia.
C Centre for Animal Conservation Genetics, Southern Cross University, PO Box 157, Lismore, NSW 2480, Australia.
D Corresponding author. Email: james.knight@dpi.nsw.gov.au
Marine and Freshwater Research 60(1) 34-44 https://doi.org/10.1071/MF08022
Submitted: 30 January 2008 Accepted: 22 October 2008 Published: 29 January 2009
Abstract
The maintenance of genetic diversity and gene flow in threatened species is a vital consideration for recovery programs. The endangered Oxleyan pygmy perch Nannoperca oxleyana has a fragmented distribution within coastal freshwater drainages of southern Queensland and northern New South Wales, Australia. In the present study, mitochondrial DNA control region variation was used to assess genetic diversity and structure across the geographical range of this species. Haplotypic diversity was highest in a small NSW subcatchment south of Evans Head (h = 0.594) followed by Marcus Creek in Queensland (h = 0.475). Distinct genetic differentiation was evident among the Queensland localities and the NSW subcatchments, implying restricted gene flow between coastal river systems. One of the nine haplotypes detected was distributed over 83.4% of the species’ range, suggesting historical connectivity among the now fragmented populations. These patterns were concordant with eustatic changes associated with the last glacial maximum. High barrier sand dunes may also act as barriers to gene flow and dispersal between adjacent NSW subcatchments. Conservation efforts should focus on the preservation of genetic diversity by maintaining as many genetically differentiated populations as possible. The relatively diverse populations inhabiting the South Evans Head subcatchment and Marcus Creek require special management consideration.
Additional keywords: floodplain connectivity, fragmentation, genetic diversity, mitochondrial DNA, population structure, wallum.
Acknowledgements
This paper is from PhD research by J. Knight, supported by the Australian Research Council, NSW Department of Primary Industries (DPI) and Southern Cross University, Lismore. We thank J. Hughes for providing the Queensland haplotype sequence data and the numerous NSW DPI staff that assisted with sample collection. We also thank A. Arthington, D. Gilligan, J. Hughes, D. Jerry and an anonymous referee for comments on drafts of the manuscript. Sample collection was approved by the animal care and ethics committees of NSW DPI (ACEC Ref. 02/09) and Southern Cross University (Authority No. 03/14).
Balcombe, S. R. , Bunn, S. E. , McKenzie-Smith, F. J. , and Davies, P. M. (2005). Variability of fish diets between dry and flood periods in an arid zone floodplain river. Journal of Fish Biology 67, 1552–1567.
| Crossref | GoogleScholarGoogle Scholar |
Donaldson, K. A. , and Wilson, R. R. (1999). Amphi-panamic geminates of snook (Percoidei : Centropomidae) provide a calibration of the divergence rate in the mitochondrial DNA control region of fishes. Molecular Phylogenetics and Evolution 13, 208–213.
| Crossref | GoogleScholarGoogle Scholar | CAS | PubMed |
Griffith, S. J. , Bale, C. , Adam, P. , and Wilson, R. (2003). Wallum and related vegetation on the NSW North Coast: description and phytosociological analysis. Cunninghamia 8, 202–252.
Hedrick, P. (2005). ‘Genetic restoration’: a more comprehensive perspective than ‘genetic rescue’. Trends in Ecology & Evolution 20, 109.
| Crossref | GoogleScholarGoogle Scholar |
Jerry, D. R. , and Baverstock, P. R. (1998). Consequences of a catadromous life-strategy for levels of mitochondrial DNA differentiation among populations of the Australian bass, Macquaria novemaculeata. Molecular Ecology 7, 1003–1013.
| Crossref | GoogleScholarGoogle Scholar | CAS | PubMed |
Knight, J. T. , and Arthington, A. H. (2008). Distribution and habitat associations of the endangered Oxleyan pygmy perch, Nannoperca oxleyana Whitley, in eastern Australia. Aquatic Conservation: Marine & Freshwater Ecosystems 18, 1240–1254.
| Crossref | GoogleScholarGoogle Scholar |
Page, T. J. , and Hughes, J. M. (2007). Phylogeographic structure in an Australian freshwater shrimp largely pre-dates the geological origins of its landscape. Heredity 98, 222–231.
| Crossref | GoogleScholarGoogle Scholar | CAS | PubMed |
Rahel, F. J. (2007). Biogeographic barriers, connectivity and homogenization of freshwater faunas: it’s a small world after all. Freshwater Biology 52, 696–710.
| Crossref | GoogleScholarGoogle Scholar |
Ward, R. , Woodwark, M. , and Skibinski, D. O. F. (1994). A comparison of genetic diversity levels in marine, freshwater and anadromous fishes. Journal of Fish Biology 44, 213–232.
| Crossref | GoogleScholarGoogle Scholar |