Sea squirt

Chordata – Ascidiacea


Attached to the reef, sea squirts (or ascidians) are often mistaken for sponges. These simple animals are practically a ‘sac’ with two openings that siphon water in and out of the body to collect food and nutrients. Sea squirts have a thick outer coat made from a cellulose-like material. This is known as the tunic, which helps protect the animal from predators.

Sea squirt, beached

Did you know?

Believe it or not, sea squirts are related to humans! In their larval stage, sea squirts have a basic backbone of rod cells (notochords), just like vertebrates, such as humans, fish and mammals. These cells are lost as the sea squirt develops into an adult.

Sea squirt, underwater