Meeting Abstract

P2.1  Sunday, Jan. 5 15:30  Behavioral Variation Between Two Clades of Leptasterias spp. CONTRERAS, A.N.*; COHEN, C.S.; California State University Long Beach; Romberg Tiburon Center, San Francisco State University ashleyn_contreras@yahoo.com

In central California, several co-occurring species of the six-rayed sea star, Leptasterias spp., are distributed in a range of environments including intertidal walls, boulders, and seagrass habitats. These direct-developing seastars have limited dispersal potential and a life history that is hypothesized to promote local adaptation. This potential for local adaptation may provide the setting for behavioral differentiation as a response to varying selective pressures among habitats. Initial field observations of two phylogenetically distinct clades from differing habitats and locations suggested that behavioral variation may relate to habitat differences among clades. To measure differences in activity, the righting response of overturned seastars was timed at both field sites. Seastars found loosely attached to seagrass at one site demonstrated a faster righting response compared to seastars firmly attached to the irregularities of rocks at another site. As a result of these field behavioral observations, more extensive tests were conducted on individuals from both clades in a common lab setting. Individual behaviors recorded included location in tank, response to food cue, aeration and mobile substrate, attachment surface, and contact with other stars. Seastars collected from mobile substrate (i.e., seagrass and kelp) showed more exploratory behaviors related to arm and tube foot movement compared to seastars collected from wave swept rocks. The experiments provide measures of behavioral variation between clades housed in a common environment, suggesting behavioral variation may be correlated with genetic or fixed phenotypic differentiation.