I got this guy from a local chain petstore and it seemed a little different from my first crab I got about 2 months ago. By different I mean he has a humongous big pincher. Here is a head on picture, You cant really tell the actual size, but hes a good 3". I noticed in the tank at the petstore he was the largest and the empty shells were definitely too small for him. As soon as I brought him home he changed into one of my larger empty turbo shells, changed back into his original and then back into the turbo! Lol Also, my first crab(who is missing his BP by the way and about an inch smaller) looks to be scared of him, hiding atop of a sea-sponge Is it OK to keep these two together? At first they were hanging upside down together.