Mating in stone crabs takes place near and offshore during the fall and can only occur when the female has molted and her shell is soft. While eggs are fertilized internally, they are eventually deposited beneath the female’s abdomen or “apron” in an external mass called a sponge. Spawning typically occurs during summer months and females can release millions of fertilized eggs in several intervals.
The eggs, which float in the water column, usually hatch within two weeks and then larval development takes approximately a month to complete. Larvae are planktonic and are transported to coastal and estuarine waters. The first larval stage to emerge from the egg is a called a zoea. As the zoea larvae grows they pass through five distinct changes before developing into a post-larval form called a megalopae. The megalopae, which is more crab-like in appearance, will settle to the bottom where it will take shelter. Here, it will molt several times before transitioning to a juvenile stone crab.
|A juvenile stone crab in my hand|
|An adult stone crab hiding under a ledge|