I used to work at the New England aquarium, and we would keep lobster and crab molts all the time for educational purposes. The sooner you can pull the molt from the tank the better. Place the molt on a paper towel and then just leave in a dry, well-ventilated area away from prying hands or paws. Sometimes it's good to place the paper towel and molt in an uncovered Tupperware dish to protect it a little more. In a couple days the connective tissue between joints, etc. will be dry and hard enough to have locked your molt in whatever position you placed it in. Obviously it is extremely fragile, but it is a super cool keepsake! I have also had success doing this with smaller molts like cleaner and fire shrimp. Do not try this with deceased animals, unless you are trying to get rid of roommates, as the stench will clear the house 🙂
Thank you! I asked my boyfriend about it, an he thought I was right creepy for wanting to keep it haha. Thank you! So, drying just means leaving it out of water till it's not wet, right? There's nothing else I should do to make it not rot?