Mussels Mytilus edulis:significant consumers and destroyers of mesozooplankton

Abstract

T h s study tested the hypothesis that mesozooplankton, particularly crustaceans, inhaled by mussels Mylus eduhs (L.) would be kiiied by ingestion, or by incorporation into pseudofaeces. Crustaceans were expected to be vulnerable because they cannot nd themselves of mucus. Field and laboratory evidence is presented to show that mussels ingest most mesozooplankton present in inhaled sea water. that some of the material is tnturated in the stomach between crystalline style and gastric shield, and that energy can be extracted from a diet of Artemia sp. indicating a degree of carnivory. Gastric processing of 'prey' anirnals is rapid (<40 min at 15 to 20C). MolIuscs and crustaceans are commonest 'prey'. Animals < 3 to 6 rnm length are ingested. Inhaled but non-ingested crustaceans become mucus-bound and are expelled in pseudofaecal particles; such animals are dead or moribund.