Contrasting Population Structure between Two Sympatric Sea Stars with Differing Life History Strategies


Meeting Abstract

37.3  Tuesday, Jan. 5  Contrasting Population Structure between Two Sympatric Sea Stars with Differing Life History Strategies PURITZ, J.B.*; KEEVER, C.C.; ADDISON, J.A.; HART, M.W.; GROSBERG, R.K.; BYRNE, M.A; TOONEN, R.J; Hawaii Institute of Marine Biology, University of Hawaii at Manoa; Simon Frasier University; University of New Brunswick; Simon Frasier University; University of California, Davis; University of Sydney; Hawaii Institute of Marine Biology, University of Hawaii at Manoa jpuritz@gmail.com

The genetic connectivity of an organism not only determines the patchiness and density of local populations but also their evolutionary independence and persistence. Here, we present results from a study designed to examine the most obvious organismal trait to affect connectivity: life history. We use mitochondrial DNA, microsatellites, and nuclear intron sequence data to examine the population structure of two sympatric sea stars, Parvulastra exigua and Meridiastra calcar, with contrasting life histories. Both species are found in the rocky shallows of Southeastern Australia and Tasmania; however, P. exigua lays benthic egg masses with crawl away juveniles while M. calcar is a broadcast spawner with lecithotrophic larvae. We show that this difference in life history affects population structure by an order of magnitude as well as profoundly influencing genetic diversity and effective population size. In contrast, we will also show that despite such differences in contemporary connectivity, that both species show similar patterns of post-Pleistocene dispersal. Implications of these results will be discussed in a broader marine conservation context.

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