Crabs, Hermit

This crab does not have a hard shell like the others, only its claws and head are calcified, so it seeks shelter in the empty shells of marine snails, moving to larger shells as it grows. The Hermit’s last two pair of legs are modified to hold onto the borrowed shell, holding so tight that it will be pulled apart if forcibly remove it from the shell. If threatened, the Hermit Crab retracts into the shell, closing off the opening with its hard claws. One claw (the right) is larger, but unlike the Fiddler Crabs, this trait is shared by both males and females.

Hermit Crabs live in shallow, protected waters. The marine Hermits found on Hilton Head are different than the land based Hermits sold in pet stores, and cannot survive out of the water for long periods.A walk around Mitchelville Beach or around the heel at low tide may reveals dozens of beautiful shells, but more often than not, these shells have a Hermit lurking inside.


When it is time to reproduce, the male and female come partially out of their shells and the male deposits a spermatophore (a capsule containing sperm), fertilizing thousands of eggs along the female’s abdomen. She carries the eggs for a month or so before hatching the eggs in the ocean. These undeveloped Hermit Crabs, called zoeae, live amongst the zooplankton as they go through several stages of development, lasting a month or two. When the immature crab reaches a stage called megalopae (it looks sorta like a tiny lobster), it finds it’s first (itty bitty) mollusk shell and starts to spend time on land. After another month or so it buries itself in the sand to molt, emerging as a full-fledged, albeit very small Hermit Crab ready to begin the endless search for larger shells as it grows.

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