Food selection by Dreissena polymorpha Pallas (Mollusca: Bivalvia)

Abstract

SUMMARY. The role of the selection systems in the mantle cavity and the stomach of Dreissena polymorpha was investigated by comparing the composition of particles in the plankton, the stomach and the mid‐gut. Both systems selected particles of 15–40 μm for food. The selection mechanism functioned more efficiently in the presence of simple algal mixtures than in the presence of lake plankton, but did not function at all in animals fed after 16 h starvation. The composition of successive pseudo‐faecal pellets differed. It is concluded that selection of different kinds of particle occurs in specific places in the mantle cavity. Cryptomonas spp. were highly preferred as food. Indications were found that not only does size‐selection occur, but also selection of a chemical nature. Copyright © 1982, Wiley Blackwell. All rights reserved