Meeting Abstract
The marine snail, Lacuna vincta, is an ecologically dominant grazer in kelp and eelgrass habitats. L. vincta exhibits inducible radula morphology dependent on current habitat, producing pointed teeth in kelp beds and blunt teeth in eelgrass beds. L. vincta adults disperse between these habitats via drifting on currents to avoid predation and to exploit seasonal shifts in resources. But dispersal behavior can result in arrival in a habitat that does not match a snail’s radula morphology. Therefore, because this inducible morphology records individuals’ histories of dispersal between these two habitat types, we used the interaction between individual-level plasticity and migratory behaviors to determine population-level characteristics of this important grazer in seasonal habitats. We surveyed two eelgrass and two kelp sites around San Juan Island, WA to assess radula mismatch and characterized flow regimes as a possible control on dispersal using novel micropython-based current speed sensors. Snails were collected during low tides from June to August 2019, dissected to extract the radula, and classified as matched, transitioning or mismatched to their current habitat. In eelgrass beds, proportions of matched snails increased over the summer, potentially reflecting the seasonal availability of eelgrass epiphytes and suggesting snail retention at these sites. In kelp beds, proportions of matched snails decreased over the summer, indicating potential high migration to and from these sites. Kelp sites had slower flow regimes than eelgrass sites. Preliminary analysis suggests a positive relationship between flow speed and radula mismatch at kelp sites, with a weaker effect at eelgrass sites. Our work shows how inducible traits can be used to quantify interactions between organism- and habitat-level ecological mechanisms in marine environments.
