J.W. Love 1 C.M. Taylor 1 A.P. Rooney 2 M.L. Warren, Jr. 3

1. Population structure of Lepomis megalotis in seasonally fragmented streams: inferences from a nested cladistic analysis J.W. Love1 C.M. Taylor1 A.P. Rooney2 M.L. Warren, Jr.3 1 Mississippi State University, Department of Biological Sciences 2 U.S.D.A. Agricultural Research Service 3 U.S.D.A. Forest Service, Oxford, MS

2. Objectives • Identify population fragmentation for Lepomis megalotis (longear sunfish) in seasonally fragmented streams • Characterize gene flow among fragmented subpopulations

3. Life History Characteristics • Gene flow influenced by dispersal capability (Zimmerman 1987) • Limited dispersal (Hasler and Wisby 1954; Berra and Gunning 1972) • Restricted movement paradigm (RMP; Gowan et al. 1994) • Relatively high immigration rate among pools in study area (I = 0.35; Taylor and Warren 2001) Lepomis megalotis (longear sunfish)

4. Turner Falls Lake Sylvia Possible Causes of Population Fragmentation Colorado River

7. Study Area

8. Objectives • Identify population fragmentation • Fragmentation related to seasonal (i.e., local) and permanent (i.e., regional) barriers to gene flow • Differentiation between subpopulations related to stream distance between them • Differentiation related to extinction of rare haplotypes (September sampling) • Characterize gene flow among fragmented subpopulations • Overall pattern of restricted gene flow consistent with the RMP

9. Haplotype Determination: D-Loop, mtDNA

10. Sequence Determination: Unique Haplotypes CAATTAAAGATTTTTTGGATTGCCCTATGAATTATTTGGAAAATGCCACAAATATTAAATATTTAGTTAGACTGT CAATTAAAGATTTTTTGGATTGCCCTATAAATTATTTGGAAAATGCCACAAATATTAAATATTTAGTAAGACTGT CGATTAAAGATTTTTTGGATTGCCCTATAAATTATTTGGAAAATGCCACAAATATTAAATATTTAGTTAGACTGT CGATTAAAGATTTTTTGGATTGCCCTATAAATTAATTGGAAAATGCCACAAATATTAAATATTTAGTAAGACTGT CGACTAAAGATTTTTTGGATTGCCCTATAAATTAATTGGAAAATGCCACAAATATTAAATATGTAGTAAGACTGT CAATTAAGGGTTCTTTAAATCACTCTATAAATTAATTAAAAAATACCACAAACACTAAACATATAATAAGATTAT CAATTAAAGATTCTTTAAATTGCTCTACAAACTAATAAAAAAATATCACAAACACTAAACATATAATGAGACTAT CAATTAAAGATTCTTTAAATCACTCTATAAATTAATCAAAAAATACTACAAACACTAAACATATAATAAAATTAT GAATTAAAGATTCTTTAGATTACCCTATAAATTAATAAAAAAATACCACAAACACTAAACATATAATAAAACTGT AGTTATAAATGGAATCCATAATATAATACAAAATTTAAAAATGATTAATATATAATGGTATGTCATCTGTCATCCTAAAAGAATAGTTTACAATCTAGTGGGATGAGGGA AGTTATAAATGGAATCCATAATATAATACAAAATTTAAAAATGATTAATATATAATGGTATGTCATCTGTCATCCTAAAAGAATAGTTTACAATCTAGTGGGATGAGGGA AGTTATAAATGGAATCCATAATATAATACAAAATTTAAAAATGATTAATATATAGTGGTATGTCATCTGTCATCCTAAAAGAATAGTCTCCAATCTAGTGGGATGAGGGA AGTTATAAATGGAATCCATAATATAATACAAAATTTAAAAATGATTAATATATAATGGTATGTCATCTGTCATCCTAAAAGAATAGTTTACAATCTAGTGGGATGAGGGA AGTTATAAATGGAATCCATAATATAATACAAAATTTAAAAATGATTAATATATAATGGTATGTCATCTGTCATCCTAAAAGAATAGTTTACAATCTAGTGGGATGAGGGA AAGCATAAACAAAATACATAATATAATACGAAACTTAAAAACAATTAGTCTATAACGACACACCATCCGCCATCCTACATGAGTAGCCTATATTCTAATAGGATGAAGGA GACCATAAACAAAATCCATAGTATCGTACAAAATTTAAAAACAATTAGTCCATAACGACACACCCTCCGCCATCCTAAATGAATAGCCTACAATCTAATGGGATGAAGGA AACCACAAACAAAATACATAATATAATACAAAATTTAAAAACAATTAATTCATAACAACACACCATCCACCATCCTAAATGAATAACCTATATTCTAATATGATGAAGAA GATCATAAACAAAATACATAGTATAATACAAAATTTAAAAACAATTAGTTTATAACAATACATCATCTGCCGTTCTAAAAAAACATCCCACACCCCAATAAAATAAAAAA

11. Population Fragmentation- AMOVA Results No Hierarchy % Var Φ-Statistic P Among sites 4.53 0.0453 0.0198 Within population 95.47 0.3744 2-region Hierarchy Between regions -1.32 ΦCT = -0.013 0.5918 Among sites 5.27 ΦSC = 0.0520 0.0203 within regions Within population 96.05 ΦST = 0.0394 0.0204 3-region Hierarchy Among regions -0.23 ΦCT = -0.0023 0.4743 Among sites 4.72 ΦSC = 0.0471 0.0392 within regions Within population 95.51 ΦST = 0.0448 0.0207

12. Population Fragmentation- Isolation by Distance r2 = - 0.11 P = 0.68

13. Population Fragmentation- Extinction L. megalotis F. olivaceus I. punctatus E. whipplei L. umbratalis L. megalotis F. olivaceus E. whipplei L. megalotis E. whipplei Haplo A Haplo B Haplo C Haplo D Haplo E Haplo A Haplo C Haplo E Haplo A Haplo C Extinction

14. Population Fragmentation- Nested Subsets P [T < 14.35º] = 0.0375

15. Characterizing Fragmentation- Haplotype Network

16. Characterizing Fragmentation- Nested Cladistic Analysis Results Table 3. Inferences suggested by Templeton (1998) for results from a nested cladistic analysis. These inferences are based on significance tests from Figure. Clade Chain of inference Inference Haplotypes nested in 1, 2, 11, 12 Contiguous range expansion Clade 1-1 One-step clades nested 1, 2, 11, 12 Contiguous range expansion in 2-1 Two-step clades nested 1, 2, 3, 4, NO Restricted gene flow with in total cladogram isolation by distance

17. Conclusions • Subpopulations of L. megalotis are significantly differentiated, but among region differences were less important than among site differences • Extinction processes influenced population fragmentation rather than geographic distance among sites • While L. megalotis exhibits restricted gene flow, long-range movement is probable and may contribute to recolonization of extirpated subpopulations

18. Future Directions • Bayesian analyses? – Corander et al. 2003 • Bottleneck effects, particularly at a site? – Luikart et al. 1998 • Demographic history? – Skyline plots, Pybus et al. 2000

19. Acknowledgements U.S.D.A. Forest Service Department of Biological Sciences (M.S.U.) Tom McElroy (Forest Products-M.S.U.) Anna Chromiack (LSBI-M.S.U.) Jim Grady (University of New Orleans) Karen Kandl (University of New Orleans) Kristine Oswald (M.S.U.) Jill Arnold (U.S.D.A.) Andy Sanders (M.S.U.)