''Ocypode'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

ghost crab Ghost crabs are semiterrestrial crabs of the subfamily Ocypodinae. They are common shore crabs in tropical and subtropical regions throughout the world, inhabiting deep burrows in the intertidal zone. They are generalist scavengers and predators ...

s found in the sandy shores of

tropical The tropics are the regions of Earth surrounding the Equator. They are defined in latitude by the Tropic of Cancer in the Northern Hemisphere at N and the Tropic of Capricorn in the Southern Hemisphere at S. The tropics are also referred to ...

and subtropical regions throughout the world. They have a box-like body, thick and elongated eyestalks, and one claw is larger than the other in both males and females. They inhabit deep burrows in the intertidal zone. They are primarily nocturnal, and are

generalist A generalist is a person with a wide array of knowledge on a variety of subjects, useful or not. It may also refer to: Occupations * a physician who provides general health care, as opposed to a medical specialist; see also: ** General pract ...

scavengers and

predator Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill th ...

s of small animals. The genus contains 21

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

Taxonomy

The genus ''Ocypode'' was first established by the German entomologist Friedrich Weber in 1795, using the

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specime ...

'' Cancer ceratophthalmus'' described by the German naturalist

Peter Simon Pallas Peter Simon Pallas FRS FRSE (22 September 1741 – 8 September 1811) was a Prussian zoologist and botanist who worked in Russia between 1767 and 1810. Life and work Peter Simon Pallas was born in Berlin, the son of Professor of Surgery ...

in 1772. ''Ocypode'' was previously the only genus classified under the ghost crab subfamily Ocypodinae until 2013, when Katsushi Sakai and Michael Türkay reclassified the

gulf ghost crab The gulf ghost crab, ''Hoplocypode occidentalis'', is a species of ghost crabs native to the Pacific coast of the Americas, from the Gulf of California to Colombia. It is the only species in the genus ''Hoplocypode''. Gulf ghost crabs are medium ...

into a separate genus, '' Hoplocypode''. It belongs to the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Ocypodidae The Ocypodidae are a family of semiterrestrial crabs that includes the ghost crabs and fiddler crabs. They are found on tropical and temperate shorelines around the world. Some genera previously included in the family are now treated as members o ...

. Ghost crabs of the genus ''Hoplocypode'' can be distinguished from those in ''Ocypode'' by examining their gonopods. In the former, the first gonopod has a complex hoof-shaped tip, while in the latter they are simple and curved.

Description

''Ocypode'' ghost crabs have deep box-like bodies. The regions on the carapace are usually not clearly defined. They have thick and elongated eyestalks with the

cornea The cornea is the transparent front part of the eye that covers the iris, pupil, and anterior chamber. Along with the anterior chamber and lens, the cornea refracts light, accounting for approximately two-thirds of the eye's total optical ...

occupying most of the lower portion. The eyestalks are also tipped with horn-like projections (styles) in seven species ('' Ocypode brevicornis'', '' O. ceratophthalma'', '' O. gaudichaudii'', '' O. macrocera'', '' O. mortoni'', '' O. rotundata'', and '' O. saratan''). Though these may be shorter or even absent altogether in juvenile specimens. While in '' O. cursor'' the eyestalks are tipped with a tuft of bristles (setae). The eyestalks are held vertically when the crab is active. Most species have pale-colored bodies that blend in well with the sand, though they are capable of gradually changing body coloration to match their environment and the time of day. The claw-bearing legs (

cheliped A chela ()also called a claw, nipper, or pinceris a pincer-like organ at the end of certain limbs of some arthropods. The name comes from Ancient Greek , through New Latin '. The plural form is chelae. Legs bearing a chela are called chelipeds. ...

s) of both sexes are unequal in size, with one much larger than the other. The palm of the claws also possess stridulating (sound-producing) ridges which they use for communication. These ridges are also important morphological characters useful for identifying species. The chelipeds are shorter than the walking legs. The last pair of walking legs ( pereiopods) is also usually shorter and thinner than the other pairs of walking legs. A cavity, with edges fringed by long setae are also found in between the bases of the second and third walking legs.

Ecology

''Ocypode'' ghost crabs construct simple to complex deep burrows in soft sandy and/or muddy substrates. They can be found in sandy beaches, rubble flats, and in estuarine areas. They are nocturnal and are

scavengers and

s of small animals.

Distribution

''Ocypode'' ghost crabs are found in

and subtropical regions throughout the world. Three species are found in the

Atlantic Ocean The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe ...

and the

Mediterranean Sea The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Western and Southern Europe and Anatolia, on the south by North Africa, and on the ...

and one in the eastern

Pacific The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the contine ...

coast of the Americas. The rest of the species are found in the western Pacific and the

Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or ~19.8% of the water on Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia to the east. To the south it is bounded by t ...

to the tip of southern

Africa Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...

Species

''Ocypode'' currently contains 21 valid species. The ghost crab formerly known as '' O. occidentalis'' was transferred to its own genus '' Hoplocypode'' in 2013. ''O. longicornuta'', ''O. platytarsis'', ''O. pygoides'' and ''O. sinensis'' were determined to be synonyms of ''O. ceratophthalma'', ''O. brevicornis'', ''O. convexa'' and ''O. cordimanus'' respectively.

References

External links

Video
of ''Ocypode ceratophthalma'' eating a moon crab in

Saint John's Island Saint John's Island also known as Saint John's is the largest of the Southern Islands in Singapore. Its indigenous Malay name is Pulau Sekijang Bendera. It is located approximately 6.5 km to the south of the main island of Singapore, off t ...

Singapore Singapore (), officially the Republic of Singapore, is a sovereign island country and city-state in maritime Southeast Asia. It lies about one degree of latitude () north of the equator, off the southern tip of the Malay Peninsula, bor ...

{{Taxonbar, from=Q13908705 Ocypodoidea