48 — Ecklonia holdfasts

Ecklonia radiata holdfast, Mount Beach, 1/10/16.

Many kinds of seaweed attach to rocks/substrates with a holdfast and over time these can become encrusted with all sorts of marine life. These holdfasts can represent micro-habitats for a variety of marine life. However, sometimes the encrustations get so large that the seaweed can no longer stay attached and gets washed off.

This is a bit of the holdfast of the kelp Ecklonia radiata. There are quite a few different wee animals to be seen... The small red things are a type of ascidian (sea squirt). The beige-coloured finger-like projections on the left are a type of sponge, and the small twig-like things are the stems of some kind of thecate hydroid.

Normally there would also be gastropod snails and various small crustaceans. But these mobile animals, which would normally make a holdfast their home, seem to know when its is doomed and make good their escape.