These look to me to be button polyps... but they are at the biggest 1mm tall and if the heads of them are open they are maybe 2mm wide. They started out on my LR as a hitchhiker about 5 months ago and the colony has propigated to about 5 times the size (5 times the size is about the size of a 50 cent piece). They do go to sleep like a polyp would once the lights go out. This picture is the best i can get. The rock can't be moved, my GBTA has decided that the best place to be is straddling this rock and another.
can anyone ID these Please.
can anyone ID these Please.