Sea Urchin's

[Crazy fishes]

I would stay well away from Diadema Spp. (black long spine urchins) they are a pain in the rear. I have one and have nothing but trouble with it when cleaning the tank. I have had more stabs from it than hot dinners and it aches for about 8 hours afterwards. Tuxedo urchins are nicer as the have shorter spines and generally hide in the day or are perched under a rock ledge. They also have the interesting feature of picking up debris to blend in with their surroundings. I would certainly go with the tuxedo urchin.

Hope this helps

Joe