Opportunistic suspension feeding in the intertidal gastropod Olivella columellaris and its implications for the regulation of tidal migrations

Abstract

The gastropod Olivella columellaris inhabits sandy beaches of the Tropical East Pacific. These snails perform tidal migrations forcontinuous suspension feeding in the moving backwash zone, possibly controlled by an endogenous circatidal clock. However, O. columellaris readily modifies its circatidal behavior, for example when flow channels develop below natural and artificial tide pools at ebb tide. Suspension feeding continues in such channels while water is running, delaying tidal migration. Such behavioral plasticity questions the significance ofendogenous rhythms for the regulation of tidal migrations in O. columellaris.