Yellow Zoanthids
Zoanthids are colonies of anemones all living and working together. They were here long before Captain Cook arrived in Sydney and Australia became one of the British colonies.
This one is aptly named the Yellow Zoanthid and can be truly spectacular in Underwater Sydney when all the anemones are in full bloom. Unfortunately to see them usually requires you to be out in the open ocean at night looking in caves and under ledges.
As that doesn't appeal to everyone (something we struggle to understand) we thought we'd take a picture and post it on this website.