I have a rainbow crab that has been in my tank for 5 months now and she all of a sudden dropped a leg couple days ago... I change her tupperwear of water every day to eveyother day, depends if i feed her wet food.. she also gets crab pellets and vegetables.... I thought she was going to molt because she stopped eating a week or more ago yet now he is falling apart.. I left home today early int he mornign to come home and find her sitting there motionless ..she looks as if she is dying her big claw fell off, another leg and the other on the same side looks none funcional she is very limp and not moving much though she is still alive.. also she is making bubbles while sitting partially out of the water.. she has no mobility unless she can walk on 3 legs.. Is this a point where it is better to euthanize? and what is a safe way to do it if nessicary.. I dont want to leave her there rotting alive.. what are my options? Do crabs molt like this? Is this a disease? poor water conditions?... I use tank water in his tupperwear.. wellthe water I use in my tanks anyways..