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Sea snakes rarely venture far from home

Authors

  • Vimoksalehi Lukoschek,

    1. ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD 4811, Australia
    2. Department of Ecology and Evolutionary Biology, University of California, Irvine, California 92697, USA
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  • Richard Shine

    1. Biological Sciences A08, University of Sydney, NSW 2006, Australia
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  • The authors thank the Australian Research Council, Sea World Research and Rescue Foundation, and The University of California, Irvine.

Vimoksalehi Lukoschek, ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD 4811, Australia. Tel: +61-7-47816294; Fax: +61-7-4781672; E-mail: vimoksalehi.lukoschek@jcu.edu.au

Abstract

The extent to which populations are connected by dispersal influences all aspects of their biology and informs the spatial scale of optimal conservation strategies. Obtaining direct estimates of dispersal is challenging, particularly in marine systems, with studies typically relying on indirect approaches to evaluate connectivity. To overcome this challenge, we combine information from an eight-year mark-recapture study with high-resolution genetic data to demonstrate extremely low dispersal and restricted gene flow at small spatial scales for a large, potentially mobile marine vertebrate, the turtleheaded sea snake (Emydocephalus annulatus). Our mark-recapture study indicated that adjacent bays in New Caledonia (<1.15 km apart) contain virtually separate sea snake populations. Sea snakes could easily swim between bays but rarely do so. Of 817 recaptures of marked snakes, only two snakes had moved between bays. We genotyped 136 snakes for 11 polymorphic microsatellite loci and found statistically significant genetic divergence between the two bays (FST= 0.008, P < 0.01). Bayesian clustering analyses detected low mixed ancestry within bays and genetic relatedness coefficients were higher, on average, within than between bays. Our results indicate that turtleheaded sea snakes rarely venture far from home, which has strong implications for their ecology, evolution, and conservation.

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