A Comment on "Mechanisms of Suspension Feeding in Bivalves: Resolution of Current Controversies by Means of Endoscopy" (Ward et al.)

Ward et al.'s (1993) claim to have resolved the controversies regarding bivalve suspension feeding is not entirely warranted. Their observations show that captured particles transported in the ventral ciliated groove end up in mucus strings. It seems doubtful whether this justifies the conclusion that binding to mucus constitutes a crucial part of the normal feeding mechanism because of contradictory evidence. Analyses of stomach contents of feeding bivalves are needed to establish the proportions of food particles that are ingested in the freely suspended state or bound in mucus. Such analyses should supplement further endoscopic studies of particle processing in the feeding structures.