This is a Ghost Crab. They are a common shore crab all over the world. You can see them on the beach on Hilton Head Island. They go from really tiny, up to a little over 2” across.
Ghost Crab on Hilton Head Island Beach
They look see-through, but actually they are just the same color as the sand. They can change colors, like a chameleon, to blend in. They can even speckle up, if the sand is speckled. They do this by adjusting the concentration and dispersal of pigments within their chromatophores, pigment cells. But, they don’t change colors very quickly. They have experimented; it takes them about a month. They also get darker at night. Really! They gradually lighten and darken on a 24 hours schedule.
If you look closely, one claw is always bigger than the other. Both male and female Ghost Crabs have one bigger claw. They are related to Fiddler Crabs. Only male Fiddler Crabs have one larger claw. Another way you can tell the difference is Ghost Crabs have long, large eyestalks with the entire lower part the corneas. Fiddler Crabs have long thin eyestalks with much smaller corneas at the tip.
They are really fast.
They are active at night, but sometimes you can see them out during the day.
They build a little burrow that they can run into if they feel threatened. They sit in the entrance and wait for food.
They dig deep burrows in the intertidal zone, the area between low tide and high tide, where the sand is damp. The smallest crabs stay closest to the water.
Ghost Crabs lay their eggs in the sea. But, once they grow up, they have to live in damp sand.
Ghost Crabs are semiterrestrial. They spend most of their time on land, but they do not have lungs. They have to go into the water often enough to keep their gills damp, so that they can absorb oxygen. You can see them running into the waves to get wet. But, they can’t live in water. They drown.
Ghost Crabs are predators and scavengers. They eat little crustaceans, like the coquinas you see all over Hilton Head beaches. They will also eat carrion, eggs, some plants… really anything they can fit into their mouths.
Raccoons eat Ghost Crabs.
