Meeting Abstract
The coastal intertidal zone contains much fine-scale habitat variation, related to a variety of abiotic factors including wave exposure. Leptasterias spp. is a genus of predatory sea stars found along the west coast of North America, and across intertidal microhabitats with varying levels of exposure to wave stress. Leptasterias spp. are limited dispersers – embryos are brooded, which may lead to differentiation or local adaptation. Preliminary data suggests behavioral differences among stars from different microhabitats that may reflect differential adaptation to prey accessibility and stressors associated with low and high wave exposure. We investigated the foraging activity of Leptasterias spp. from sites with inferred high and low wave exposure in central and northern California. Prior to collection, we estimated field prey availability by quantifying abundance in 50 cm2 quadrats surrounding individual stars. Crawl distance and prey choice were then tested in static seawater tanks and in a two-current flume tank. High and low wave-exposed sites showed different prey composition, and stars from low wave-exposed sites crawled farther than high wave-exposed stars (Mann Whitney U = 173.5, p = 0.038). Although Leptasterias spp. showed an overall tendency to detect and choose prey in a two-current flume tank (One-sample proportion test, p = 0.053), prey choice did not differ between stars of different microhabitats. Leptasterias spp. may use chemoreception in foraging, and the extent to which other behavioral differences reflect microhabitat and clade may vary.
