Ghost Crabs

Introduction
Ghost crabs are also known as sand crabs are tiny animals that are mainly terrestrial. They live in elaborate burrows. Sand crabs live their entire adult life on beaches in tropical and sub-tropical regions around the world. They prefer quiet beaches and forage for food at night when they are less apt to be seen by predators.

Where they live
Sand crabs are found along beaches from Rhode Island south to Brazil. Unlike crabs that live in the water they only need to wet their gills. In Chesapeake Bay these crabs like to brace themselves in the sand and let the waves wash over their bodies to wet their gills. They also have hairs on the base of their legs that wicks up water from damp sand to wet their gills.

Ghost crab on sand beach, NOAA

Ghost crab on a sandy beach, NOAA

What they eat
Ghost crabs are omnivores because they eat meat and vegetable matter. They eat all kinds of food they find on the beaches. Their diet includes vegetation and other debris washed in by the tides. They also feed on mole crabs, clams and the eggs of loggerhead turtles.

Predators
Predators of these tiny crustaceans include raccoons, shorebirds and gulls. Sand crabs hide in their burrows during hot sunny days. They stay in the burrows for two reasons during the day. They stay inside their burrows during the day when the hot sun heats up the beaches. It is also much harder for predators to see the tiny crabs at night than it is during daylight hours.

Tunnels they build
Ghost crabs all live in burrows that have a small opening about the size of a nickel or a quarter. They burrow down into the sand often creating an elaborate tunnel system underground. Their tunnels often go down four feet into the sand with side branches. Young sand crabs create burrows close to the water’s edge while older adults often create burrows hundreds of feet from the edge of the waves.

Reproduction
Sand crabs mate all year long and the males prefer to mate near their burrow holes. During the mating time with a female the male secretes a fluid that hardens and prevents rival male’s sperm from reaching the ova of the female. The female carries the fertilized eggs under their bodies until they are ready to hatch. She releases the eggs into the water where the larvae grow and develop into young crabs before coming ashore to live the rest of their lives.

Physical features
Ocypoda is the Latin name for ghost crabs. It means “swift-footed.” The crabs have four sets of walking legs and one pair of white claws. The adult’s carapace (shell) is usually about 2 inches long. Young crabs are much darker with a mottled gray or brown shell. Older adults have shells that are square-shaped and semi-transparent. The males are usually larger than the females and their shells can grow up to 3 inches long. They have eyestalks that are club shaped. The crabs can rotate the eyestalks 360 degrees looking for predators and food.

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