Effect of flavor and size on selection of food by suspension‐feeding plutei1

Plutei ingested plastic spheres previously incubated with algal cells at higher rates than plastic spheres incubated with filtered seawater. The attractive factor overrode or modified preferential ingestion of spheres of different sizes. The cultured algae were centrifuged and resuspended before the plastic spheres were exposed to the algal cells, so it is probable that natural materials associated with the algal cells were transferred to the plastic spheres and triggered the selective ingestion of particles. Capture on the basis of flavor could be especially important for those suspension feeders that actively respond to particles in order to capture them; if they concentrate only nutritious particles, then they avoid subsequent problems of sorting and handling. Preconditioning plutei by feeding with algal cells of one of two sizes does not increase preference for untreated spheres of the algal size.