Meeting Abstract

103.2  Sunday, Jan. 6  The function of shell wiping in the marine snail Calliostoma ligatum IYENGAR, E.V.; Muhlenberg College iyengar@muhlenberg.edu

Individuals of the marine snail Calliostoma ligatum, similar to other congeners, are unusual in that they can extend their foot over the apex of their shells and use the back of the foot to wipe the entire surface of the shell. Shell-wiping leaves behind a thin film of mucus; the removal of the mucus using a paper towel renders the shell less slippery. Various functions have been proposed for the purpose of shell-wiping in Calliostoma spp., including defense from predators and procurement of food. Because of this wiping behavior, Calliostoma ligatum shells are typically cleaner than surrounding surfaces. However, certain epibiotic species, most notably the slipper limpet Crepidula adunca, specialize on this host species. In choice experiments, individuals of Crepidula adunca were neither more or less likely to attach to wiped compared with unaltered shells of Caliostoma ligatum, nor did predators (sea stars and crabs) discriminate based on this parameter. Host snails wipe their foot over the shell of established epibiotic Crepidula adunca. At the end of a wiping bout, individuals of Calliostoma ligatum retracted their foot before it passed over the mouth, so procurement of food is an unlikely reason for shell wiping. Time lapse video documented that animals did not increase their rate of shell-wiping after the mucus had been removed from the shell. After contact with predators, snails were more likely to increase their rate of movement and did not seem to increase the frequency of shell wiping, but there was variation in this response. Thus, the shell wiping behavior in Calliostoma ligatum is more likely to have evolved to remove non-specialist fouling organisms than to encourage or discourage specialist epibionts, discourage predators, or provide food to the snail.