No one knows exactly, but aquarium studies suggest 5 to 7 years. Five, on the average. Several days if kept in a cool, moist environment. The lobster is a gill-breather, and moisture is essential to survival.
Fresh water is lethal to a lobster .
The animal has salty blood and tissue, which require a seawater environment if life is to be maintained. The red pigment is the most stable component of the coloring in a lobster shell. The greens and browns which darken the shell in a live lobster are destroyed by cooking.