Beachcombers Field Guide - Department Of Fisheries Western ...

Colonial ascidian
Chordata – Ascidiacea
A colonial ascidian is a
colony of animals (or zooids),
where it is hard to distinguish
separate animals – individual zooids
can only be seen clearly with a
microscope. They form intricate patterns
and come in an assortment of colours.
Ascidians are diffi cult to identify properly
without examining the internal structure
of the specimen.
Photo: Clay Bryce
Did you know?
Colonial ascidians usually
grow as a coating on rocks or
reefs, and can be mistaken for an
encrusting sponge. The difference
is that ascidians have a nervous
system and they respond to
touch by retracting and closing
their siphons.