I third it on the buttom polyps. No special care is required as said already, but tend to do better with brighter light and being fed once in a while. You got some good quality rock if they came on it.
Zooanthids (commonly called button polyps), but getting down to the species is almost impossible with zooanthids. I feed mine regularly (several times a week), and they grow like mad. They appreciate moderate to high lighting and moderate to mild water flow. If they are happy, they will open, as in your pictures.
i am new to reefs and set up a 12 gallon nano tank...(not new to saltwater)..some of the live rock i purchased had some stuff growing on it...polyps i think. Could someone id this stuff for me and let me know how to take care of them...
[ December 23, 2001: Message edited by: reeferbrad ]</p>
Button polyps, I've never directly fed them. They like all types of light (IME). I do have a heavy feeding of misc. stuff for my other corals and fish though.