1. Preparation: As the crab grows, its body becomes too big for its current exoskeleton. Inside the old shell, the crab starts to produce a new, larger shell beneath the old one.
2. Pre-molt: Before the molt, the crab absorbs calcium and other minerals from its old shell to store in its body. This helps in the formation of the new exoskeleton.
3. Splitting the Shell: The crab's body will start to withdraw from the old shell. A split or rupture usually forms along the back of the crab's carapace (the hard upper shell).
4. Emerging from the Shell: The crab slowly pulls itself out of the old exoskeleton. This can take several hours, and the crab is vulnerable and immobile during this process.
5. Rapid Expansion: Once free from the old shell, the crab's body rapidly expands and absorbs water. This causes the new exoskeleton to stretch and harden.
6. Hardening: The new exoskeleton is initially soft and flexible. Over time, it hardens through a process called calcification, where calcium and other minerals are deposited in the shell.
7. Growth and Feeding: After molting, the crab's body is soft and vulnerable, so it typically hides and rests until the new exoskeleton hardens. During this time, the crab doesn't feed much.
8. Post-molt: Once the new exoskeleton is fully hardened, the crab can resume feeding and continue its growth cycle.
Crabs molt multiple times throughout their lives, each time growing larger. The frequency of molting varies among different species and depends on factors like age, environmental conditions, and food availability.