Why do decapod crustaceans prefer small-sized molluscan prey?

Abstract

A survey of studies examining crab and lobster predation on hard-shelled molluscs indicated that most predators prefer small-sized prey when offered a range of sizes. This pattern of preference can be explained by considering the mechanical cost of predation. If predation costs are assumed to be non-renewable, then the probability of exhausting them can be included as an additional parameter in the classical diet breadth model. -from Author