Red Sea Squirt

WHAT DOES IT LOOK LIKE?

The red sea squirt (Halocynthia papillosa) looks like a small pouch that can be rounded or elongated. It is bright red, sometimes with an orange tinge. Its thick outer covering, called the tunic, is covered in small bumps.

Two siphons, the body openings, stand out on this pouch, one towards the top and the other at the side.

WHERE DOES IT LIVE?

Shaded parts of rocks, drop-offs and walls are common red sea squirt habitats. Attached to a hard surface, it often remains exposed to moderate current. Surface orientation and shade cast by the structure are useful features when locating suitable positions.

WHAT DOES IT EAT?

The red sea squirt’s food combines minute living organisms with non-living organic particles. Bacteria, diatoms and ciliates are among its food resources. Water brings them into the branchial sac, where the internal filter retains them. Bound in mucus, particles are then carried towards the stomach by beating cilia. The animal therefore takes a range of suspended foods rather than microscopic algae alone. The contribution of different resources changes with the foods available in the water.