I was at my LFS yesterday and they had some mini purple lobsters, the guys are so colorful, I'd really like to add one to the tank. It may be a problem though as I've got a hi-fin red banded shrimp goby that stays on the sand bed near the rocks. I'm sure the lobsters are opportunistic like the crabs, but wondered if they were just a bad idea all together. I've got a 55 with about 80-90 lbs live rock and some various corals (xenias, zoos, mushrooms, and a colt).