Swallow, filter, suck in: surprising ways to feed

Four meals beneath the surface

A mussel snaps its shell shut. A sea star settles over it. All it needs is a tiny gap. Elsewhere, a fish uses rushing water to catch a shrimp, and a sea cucumber finds food between grains of sand.

By DIVE.EXPLO360.FR · 11/11/2026

A stomach that reaches out

The sea star holds on with tiny tube feet under its arms. If the two halves of the shell part a little, it can push its stomach out through its mouth to reach the soft flesh.

A sea star and a mussel on rocky ground. — The tube feet grip the valves. A tiny gap can give access to the tissue. © dive.explo360.fr — All rights reserved. Reproduction requires permission.

A sea squirt attached to a rock, with two openings. — Water enters through one siphon and leaves through the other. © dive.explo360.fr — All rights reserved. Reproduction requires permission.

Two openings, one current

A sea squirt lives attached to a rock. Look at its two openings. Water enters through one and leaves through the other, bringing tiny pieces of food.

Where is the food?

Inside a shell

The sea star reaches tissue through a gap.

In the water

A sea squirt traps particles and a fish can suck in prey.

In the sediment

The sea cucumber gathers particles deposited on the bottom.

A net made of mucus

Inside the sea squirt is a fine net made of mucus, a sticky substance the animal makes. Tiny bits of food get caught in it. The sea squirt swallows the net and the food together.