Can't really tell but it almost looks like a small barnacle shell...
And that star is having a file fish snack!!!!
If the 40 is going to be a reef, that won't work so well. They are not reef-safe at all. My Harlequins would love to see that guy!
I have no idea what it is, but i had one that was stuck on a large asterea snail i had gotten via group buy. I didn't want to introduce something i couldn't identify so I pulled out a flat head screwdriver to ply the thing off. It reminded me of some parasite I've seen on Star trek...LOL.First the question. What is this thing on the turbo snail I just got?