While tunicates are almost all filter feeders, eating phytoplankton and other small particles, there are several deep-sea species of ascidians

, chiefly in the family Octacnemidae (Phlebobranchia), in which the oral or incurrent siphon is enlarged to form a mouth that can capture large prey.

How do tunicates feed?

Tunicates are plankton feeders. They live by drawing seawater through their bodies. Water enters the oral siphon, passes through a sieve-like structure, the branchial basket that traps food particles and oxygen, and is expelled through the atrial siphon.

Do tunicates have predators?

They pump water in through one siphon, filter the plankton and other small food particles through their digestive system, and then release the filtered water out through the other siphon. Adult tunicates have few predators because of their thick and noxious skin. Crabs, sea stars or snails may eat juvenile tunicates.