Short Communication Prey Capture Hydrodynamics in Fishes: Two Approaches

Abstract

Suction feeding is widely used in teleost fish (<20 000 species). It is accomplished by rapid expansion and contraction (<100 ms) of the buccal and opercular cavities and results in movement of both the prey and the fish itself. Suction is often combined with jaw protrusion and swimming. During a single suction movement the volume of water passing through the mouth aperture may exceed, by more than five times, the volume of the fully expanded mouth cavity, since after a given moment water leaves the mouth through the opercular slits. The generated flow is highly unsteady, i.e. large local accelerations (>50m s−2) occur and streamline patterns change rapidly with time.