Facts: The Blackback Land Crab

The blackback land crab is a colorful, reddish-orange crab with a black spot on its carapace. The crabs are found along the eastern Atlantic and Gulf of Mexico coastlines, including the islands of the Caribbean. Blackback land crabs burrow in marshes, mangroves, and beaches. A crab's burrow leads to a living chamber that is used for food storage and as a retreat during dry conditions. The burrows can be up to 3 ft long. The crabs need to enter saltwater shallows in order to moisten their gills. They must also return to the ocean to breed. In the ocean, crab larvae are released into the water. The crabs grow to about 4.5 in wide. They are mainly herbivores, coming out of their burrows to forage on plants at night, but they will also feed on animal matter. In areas like the island of Bermuda, these crabs often cause damage to crops. When blackback land crabs molt, they create a temporary shell using a combination of air and internal fluids to increase the pressure inside of their bodies. This air skeleton creates a temporary tightness until their newly secreted larger shell hardens. Whenever there is a rain shower, the crabs immediately become active. For example, in southeastern Florida, when rains are frequent, large numbers of these crabs can be seen out of their burrows by day. Otherwise, it is unusual for this species to be active during daylight hours. The crabs are sometimes consumed by humans. For more marine facts, click the SUBSCRIBE button.