It’s always fun discovering new things about the plants and animals that share our beaches. Ghost crabs, for instance, sometimes eat other ghost crabs. There are other interesting facts about this common beach resident. The same species of ghost crab (Ocypoda quadrata) lives from Rhode Island to Brazil. They blend in well with the beach and when threatened, disappear down burrows they dig in the sand. Above their two-inch-wide bodies are bulging eyes on the end of stalks that swivel independently; ghost crabs can see forward and backward simultaneously. Like other decapods (crabs) they have ten legs, eight for scuttling and two for pinching.
Though adult ghost crabs are terrestrial, they return to the water to keep their gills moist. Perhaps you’ve seen ghost crabs hold tight onto the sand as waves wash over them. They are wetting their gills. They can also wet their gills by standing in damp sand and wicking moisture up their hairy legs.
Ghost crabs mate year round. Males lure females to their burrows, and along with sperm, insert a fluid which hardens, thus ensuring that other males won’t fertilize their mate’s eggs. Females carry fertilized eggs underneath their body until they are ready to hatch and then release the eggs into the ocean. After several planktonic larval stages, the lucky ones wash ashore as little crabs.
During the warmest part of the day, ghost crabs hunker down in their burrows with a plug of sand closing off the opening. They emerge when the sun goes down. The best time to hunt ghost crabs is when it gets dark. Shine a light in their eyes and watch them freeze. Scoop them up with a net, put them in a bucket, release them when the hunt is over. In the photo, children in Malaysia tie strings to ghost crab legs so the crabs can’t escape while they are being played with. Ghost crabs make good temporary pets that can be released when the thrill wears off. Put them in a tank with plenty of sand to dig in and a bowl of salt water to keep their gills moist. Feed them.
Ghost crabs eat just about anything, each other and donuts included. Coquina clams and mole crabs from the swash zone make up the bulk of their diet with seaweed and dune plants on the side. When sea turtle eggs and hatchlings are in season, they feast on those too.
A lot of animals feast on sea turtle hatchlings and eggs, including raccoons. In an effort to save the sea turtles, raccoons were removed from a beach. This caused the ghost crab population to swell because raccoons weren’t there to eat ghost crabs. Sea turtle casualties rose even higher than before the raccoons were removed. We want to help, but interfering with the food chain doesn’t work. Instead, lend a hand and clean up plastic on our shores and in our oceans. Grab a clean, used bag from the BlueTube at your beach. Pick up plastic trash that has washed ashore. Throw it away. If your shore doesn’t have a BlueTube, sponsor one today!