Crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting tail-like abdomen, usually hidden entirely under the thorax. They live in all the world's oceans, in freshwater, and on land, are generally covered with a thick exoskeleton, and have a single pair of pincers on each arm. They first appeared during the Jurassic period, around 200 million years ago.
Grapsus grapsus is one of the most common crabs along the western coast of the Americas. It is known as the red rock crab, or, along with other crabs such as Percnon gibbesi, as the Sally Lightfoot crab.
Mictyris is a genus of brightly coloured crabs, placed in its own taxonomical family, the Mictyridae. It inhabits the central Indo-West Pacific region. These crabs congregate on mud flats or beaches in groups of a few thousand, and filter sand or mud for microscopic organisms. They congregate during low tide, and bury themselves in the sand during high tide or whenever they are threatened. This is done in wet sand, and they dig in a corkscrew pattern, leaving many small round pellets of sand behind them.
Red rock crab may refer to several species of crab:
The Grapsidae are a family of crabs known variously as marsh crabs, shore crabs, or talon crabs. The family has not been confirmed to form a monophyletic group and some taxa may belong in other families. They are found along the shore among rocks, in estuaries, marshes, and in some cases pelagic among drifting seaweeds and flotsam.
Leptograpsus variegatus, known as the purple rock crab, is a marine large-eyed crab of the family Grapsidae, found in southern subtropical Indo-Pacific Oceans. It grows to around 50 millimetres (2.0 in) shell width. It is the only species in the genus Leptograpsus.
Plagusia squamosa is a marine crab of the family Plagusiidae, formerly considered a subspecies of Plagusia depressa. It is found in tropical Indo-Pacific oceans. P. squamosa's carapace is bumpy and quite coarse, seemingly scaly, leading to its common name: The Scaly Rock Crab.
Xanthoidea is a superfamily of crabs, comprising seven families. Formerly, a number of other families were included in Xanthoidea, but many of these have since been removed to other superfamilies. These include Carpilioidea, Eriphioidea, Hexapodoidea, Pilumnoidea and Trapezioidea. Even in this reduced state, Xanthoidea remains one of the most species-rich superfamilies of crabs.
Eubrachyura is a group of decapod crustaceans comprising the more derived crabs. It is divided into two subsections, based on the position of the genital openings in the two sexes. In the Heterotremata, the openings are on the legs in the males, but on the sternum in females, while in the Thoracotremata, the openings are on the sternum in both sexes. This contrasts with the situation in other decapods, in which the genital openings are always on the legs. Heterotremata is the larger of the two groups, containing the species-rich superfamilies Xanthoidea and Pilumnoidea and all the freshwater crabs. The eubrachyura is well known for actively and constantly building its own burrows. The fossil record of the Eubrachyura extends back to the Cretaceous; the supposed Bathonian representative of the group, Hebertides jurassica, ultimately turned out to be Cenozoic in age.
Percnon gibbesi is a species of crab. It is one of at least two species commonly called Sally Lightfoot, and is also referred to as the nimble spray crab or urchin crab. It has been described as "the most invasive decapod species to enter the Mediterranean".
Sally Lightfoot may refer to:
Pachygrapsus marmoratus is a species of crab, sometimes called the marbled rock crab or marbled crab, which lives in the Black Sea, the Mediterranean Sea and parts of the Atlantic Ocean. It is dark violet brown, with yellow marbling, and with a body up to 36 millimetres (1.4 in) long. A semiterrestrial omnivore, it feeds on algae and various animals including mussels and limpets.
Epialtidae is a family of crabs, containing the subfamilies:
Tortuga Bay is located on the Santa Cruz Island, about a 20-minute water-taxi ride from the main water taxi dock in Puerto Ayora. There is also a walking path, which is 1.55 miles (2,490 m) and is open from six in the morning to six in the evening. Visitors must sign in and out at the start of the path with the Galapagos Park Service office. Tortuga Bay has a gigantic, perfectly preserved beach that is forbidden to swimmers and is preserved for the wildlife where many marine iguanas, galapagos crabs and birds are seen dotted along the volcanic rocks. There is a separate cove where you can swim where it is common to view white tip reef sharks swimming in groups and on occasion tiger sharks
Geograpsus lividus is a species of crab in the family Grapsidae. Little research has been conducted on this species. It was originally classified as belonging to the genus Grapsus; however, this name is no longer used.
Grapsus albolineatus is a species of decapod crustacean in the family Grapsidae, native to the Indo-Pacific.
Grapsus tenuicrustatus, commonly known as thin-shelled rock crab or Natal lightfoot crab, is a species of decapod crustacean in the family Grapsidae.
Grapsus longitarsis is a species of crab in the family Grapsidae, native to the Indo-Pacific. It was first described by James Dwight Dana in 1851, from a specimen found in the Tuamotu Archipelago, French Polynesia.
Grapsus adscensionis is a species of crab found in the eastern Atlantic Ocean.
