I recently got some rock from TBS for my IM 25 Lagoon. Just curious on a few of these. I believe I have about 3 porcelain crabs, a pencil urchin (?), and an unknown crab. I found him eating another crab last night. I don’t see any black on his claws, but just checking before I start adding coral and fish! And any suggestions on catching these guys if need be?