I live in Louisiana, and we have blue crabs from the gulf of Mexico. We keep them alive overnight if we don't want to eat them that day.
How To Keep A Blue Crab Alive Overnight So You Can Cook It The Next Day
After we go crabbing, we have to keep them alive before we are ready to boil them, and the only way we can keep them alive is to put them on ice. We keep them in an ice chest with a couple inches of water and a bag of ice. This works for about 12 hours.