Sorry i thought i spelled it wrong mental note..HANNAH..don't be mad lol............PRC if those are aiptasia.i should stop selling them those are some kind of little star polyp.they are white,pink,brown,or purple depending on light and flow.and they grow in a mat just like gsp.my buddy has a 5x5 piece under metal halides and they are brown with glowing purple tips.but thanks for your concern.but that little rock has been in my tanks for almost a year now and they don't spread anywhere but that rock.and they never get bigger than what you are seeing.They just look like hell because i keep peeling them off and thinning them out to let the zoas/palys grow more.and you cant see it in the pictures but my clown fish fry play in those star polyps.Thanks and happy tanks