Live Rock hitchhiker ID (pic included)

[GoSUV]

Came with my LR. Just wanted to know what it is. It has grown to about twice its size since I got the rock a few months ago. Doesn't seem to need much light to survive as I only have one strip of normal output bulb of 20W.

Hope this picture is clear enough.

[ian cooper]

Looks like a zooanthid polyp. The green centre will most likely fluoresce (sp?) under actinics. See if you can provide a little more light and eventually it will grow into several colonies. In my experience, they are also very adept at catching food, too. You have to love free inverts!

[afss]

Agreed, To me it looks like what i know as (common name) sand polyps. They are great at grabing food, and seem to grow fairly rapidly.
good luck
Scott