A. The crab cells will puff up after sitting in distilled water for too long because osmosis is the movement of water molecules from high —> low concentration of water through the permeability of the cell membrane. This isn’t controllable so without any will, the Crab is taking in 100% distilled water while the Crab’s normal water content could be 3% salt and 97% water.
B. Sorry I actually have no idea for this one.