The meal begins outside
The sea star grips and pulls on the mussel’s valves with its tube feet. Once a gap opens, the cardiac stomach can turn outwards through the mouth. This eversion brings the stomach into contact with the bivalve’s exposed tissue, where digestion begins.
Two openings, one current
Water enters through the incurrent siphon and crosses the sea squirt’s perforated pharynx before leaving through the excurrent siphon. Beating cilia help drive the flow.
A net made of mucus
The endostyle secretes a fine net of mucus that traps suspended particles. Water continues towards the outlet, while the food-laden mucus takes a different route into the gut.
