kids encyclopedia robot

Atlantic ghost crab facts for kids

Kids Encyclopedia Facts
Quick facts for kids
Atlantic ghost crab
Ocypode quadrata (Cahuita).jpg
Adult O. quadrata by a burrow entrance
Juvenile Atlantic Ghost Crab.JPG
Juvenile O. quadrata
Scientific classification
Kingdom:
Phylum:
Subphylum:
Class:
Order:
Infraorder:
Family:
Ocypodidae
Genus:
Ocypode
Species:
O. quadrata
Binomial name
Ocypode quadrata
(Fabricius, 1787) 
Synonyms
  • Cancer quadrata Fabricius, 1787
  • Ocypode albicans Bosc, 1802
  • Monolepis inermis Say, 1817
  • Ocypode arenarius Say, 1817

The Atlantic ghost crab, Ocypode quadrata, is a species of ghost crab. It is a common species along the Atlantic coast of the United States, where it is the only species of ghost crab; its range of distribution extends from its northernmost reach on beaches in Westport, Massachusetts, south along the coasts of the tropical Western Atlantic Ocean to the beach of Barra do Chui, in Rio Grande do Sul in southern Brazil.

Description

Adults are greyish or the color of straw, and around 5 cm (2.0 in) wide at maturity. They must return to water periodically to moisten their gills, and when larvae must be released into the sea, but are otherwise terrestrial. Their stalked compound eyes can swivel to give them 360° vision. Young crabs are cryptically colored to blend in with their sandy habitats.

Distribution

Atlantic ghost crabs are found from Block Island, Rhode Island, and Nantucket, Massachusetts, northern Virginia beaches, to Santa Catarina, Brazil, on Fernando de Noronha, and Bermuda. Its planktonic larvae have been found even farther north, at Woods Hole, Massachusetts, although the adults cannot survive there.

Fossil record

Fossil specimens of O. quadrata have been found in rocks dating from the Pleistocene.

Ecology

Atlantic ghost crab of Rehoboth Beach 2020c
Atlantic ghost crab of Cape Henlopen State Park near Rehoboth Beach, Delaware in 2020

The Atlantic ghost crab lives in burrows in sand above the strandline. Older individuals dig their burrows farther from the sea, some starting as much as 400 m (1,300 ft) inland. Burrows can be up to 1.3 m (4 ft 3 in) deep, and can be closed off with sand during hot periods.

This crab can produce a variety of sounds by striking the ground with the claw, by stridulation with the legs, and an incompletely explained "bubbling sound". Males compete in a heavily ritualised manner which prevents the need for physical contact.

O. quadrata is more active at night than in the day, and is an omnivore, eating clams, insects, plant material, detritus, and even other crabs.

Sandy beaches, a habitat frequented by ghost crabs, have had a decrease in the abundance of ghost crabs due to human behavior. Ghost crabs are negatively impacted by human and vehicle trampling, which results in direct crushing of crabs, as well as indirect damage such as compression of sediment which reduces habitat suitability, interference with reproductive behaviors, reduction in food supply, and light pollution. Consequently, it is less common on beaches frequented by people.

kids search engine
Atlantic ghost crab Facts for Kids. Kiddle Encyclopedia.