I got up this morning and like always peeked into the tank to see how the kiddies were doing. I panicked when I looked into the deep ocean basin and saw red legs underneath some pieces of aquarium plant. I opened the top and took the plant off the top of the crab and he retracted into his shell confirming that he was alive. So I decided not to touch him and just watch. I stood by the tank for a full TEN MINUTES! and watched as he stayed under--completely under the water. I don't know how long he was there before I got up, but I have just witnessed him staying submerged for a period of 10 minutes~very interesting. I added this new pond only a week ago. Prior to that they had dishes that were about 2 inches deep and he did sit in that one on occassion for quite some time. Three days ago, I saw him "jump" (hehe) into the deep end of the ocean basin and go under and then come right back out-like he was testing it out LOL Has anyone else sat and timed their straws that submerge?