Unidentified filter feeder

[jjt305]

Recently I have noticed an anemone looking critters popping up on my live rock. They are about 1/8" to 1/4" inch tall and have a green disk center with a single row of very fine tentacles around the disk. They expand and contract at times and my fish don't seem to bother them. I'm not sure what they are please advise.

 

[steve-s]

Looks like a hydroid polyp but what type I couldn't tell you. Sometimes they can spread like wild fire while in some tanks they wax and wane. Unless it starts multpilying wildly, I wouldn't worry too much.

Cheers
Steve