Meeting Abstract

P2.60  Jan. 5  Microsatellite Variation and Mating System Characterization in Asterinid Sea Stars KEEVER, C.C.*; HART, M.W.; Simon Fraser University; Simon Fraser University ckeever@sfu.ca

We study mating system evolution in four clades of asterinid sea stars that have independently evolved hermaphrodite adults that produce non-dispersing larvae in benthic egg masses or internal brood spaces. Some degree of self-fertilization has been documented, there is some evidence of brood cannibalism, but otherwise these mating systems are unknown. We use microsatellite allelic variation within broods and between parents and offspring to identify cases of self-fertilization and outcrossing, and to assess the extent of multiple paternity among outcrossed offspring. One outcome of early comparisons is the discovery that these microsatellite loci are surprisingly invariant compared to patterns of within-population variation at the same loci in asterinids with planktonic larval development. Data from other markers and from other hermaphrodite asterinids with non-planktonic development suggest that inbreeding (mating among relatives) might not be a general explanation for the relatively low rate of microsatellite polymorphism in these populations. In addition to viewing and discussing our study of mating system evolution, we invite you to discuss possible explanations for differences in the amount of microsatellite variation between species with different mating systems.