Was observing our blue legged hermit crabs in the refugium and noticed what looked quite like a baby brittle star. At first I only saw the legs so I thought it was bristle worms, but then noticed that the arms all attached to a central body and appeared to be moving in co-ordination. I believe this animal was brought down from the display tank on a bit of sponge I removed from the rock there. I noticed the "worms" at that time but didn't see the central body until last night.