What exactly will these guys eat in a reef tank? Will they just eat crabs/shrimps, or will they eat corals too. I'm thinking of placing one in an SPS tank.
Yeah, they will eat your inverts but won't eat your corals. They will knock corals and rocks over in search of food if they are not secured, but they will not eat the corals themselves.
yeah i just got one off of divers den a week or so ago. he is 6" long. i had him with corals and snail and smaller fish. he didnt touch any of them. im sure if i threw a shrimp in there or a crab it would be toast. but then again i also have a porcupine puffer that would eat them too. however i have had small tuskfish in my girlfriends reef aquarium and it was 100% reef safe. it was too small to eat any shrimp or anything so if you want to add them to a reef you can as long as it is under 3 inches and your inverts are in there first. the good news is in my experience with tuskfiish they dont grow very fast. so you will be able to enjoy it for quite sometime.