Mattisimo
Reefing newb
Hello all! I am brand new to this, so I may be asking a question with an obvious answer, but here goes. I just added live rock to my tank a couple of days ago- and this little guy popped out last night. He opens and closes like an umbrella, and sometimes goes all the way back into his hole in the rock. He's purple and about a centimeter in diameter. I'm just wondering what he is. Any help in identifying him would be great. I am excited that something is alive in my tank. Cheers!