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.
King crabs are decapod crustaceans in the family Lithodidae that are chiefly found in cold seas. Because of their large size and the taste of their meat, many species are widely caught and sold as food with the most common being the red king crab.
Carcinisation is a form of convergent evolution in which non-crab crustaceans evolve a crab-like body plan. The term was introduced into evolutionary biology by L. A. Borradaile, who described it as "the many attempts of Nature to evolve a crab".
Gilvossius tyrrhenus is a species of thalassinidean crustacean which grows to a length of 70 mm (2.8 in). It lives in burrows in shallow sandy parts of the sea-bed in the Mediterranean Sea and northern Atlantic Ocean. It is the most common thalassinidean in the Mediterranean, and has been used as bait by fishermen for at least 200 years.
Squilla mantis is a species of mantis shrimp found in shallow coastal areas of the Mediterranean Sea and the Eastern Atlantic Ocean: it is also known as "pacchero" or "canocchia". Its abundance has led to it being the only commercially fished mantis shrimp in the Mediterranean.
Lithodes santolla, also known as the southern king crab, Chilean king crab or centolla, is a species of king crab, found off southern South America including the offshore Falkland Islands. On the Pacific side, it is found in Chile from Talcahuano to Cape Horn. On the Atlantic side, it is found off Argentina and Uruguay. It lives in the benthic zone at depths of 0–700 m (0–2,300 ft), with Uruguayan records being exclusively from great depths. In Chile, it mostly lives at depths to 150 m (490 ft), but south of 40° S it can be found to 600 m (2,000 ft). It is a large crab that can reach up to 19 cm (7.5 in) in carapace length, and it is the target of commercial fishing.
Goneplax rhomboides is a species of crab. It is known by the common name angular crab because of its angular carapace. Although it is also called the square crab, its shell is in fact more trapezoidal than square. This species is also known as the mud-runner because they are able to run away quickly when threatened.
Xantho poressa, the jaguar round crab, is a species of crab from the eastern Atlantic Ocean. It is one of four species in the genus Xantho.
Crustaceans may pass through a number of larval and immature stages between hatching from their eggs and reaching their adult form. Each of the stages is separated by a moult, in which the hard exoskeleton is shed to allow the animal to grow. The larvae of crustaceans often bear little resemblance to the adult, and there are still cases where it is not known what larvae will grow into what adults. This is especially true of crustaceans which live as benthic adults, more-so than where the larvae are planktonic, and thereby easily caught.
Pisidia longicornis, the long-clawed porcelain crab, is a species of porcelain crab that lives in the north-eastern Atlantic Ocean. It varies from reddish to white, and grows to a carapace width of 1 cm (0.4 in). It was first named by Carl Linnaeus in 1767, although the etymology remains unclear.
Lithodes is a genus of king crabs. Today there are about 30 recognized species, but others formerly included in this genus have been moved to Neolithodes and Paralomis. They are found in oceans around the world, ranging from shallow to deep waters, but mostly at depths of 100–1,000 m (300–3,300 ft). They are restricted to relatively cold waters, meaning that they only occur at high depths at low latitudes, but some species also shallower at high latitudes. They are medium to large crabs, and some species are or were targeted by fisheries.
Calcinus tubularis is a species of hermit crab. It is found in the Mediterranean Sea and around islands in the Atlantic Ocean, where it lives below the intertidal zone. Its carapace, eyestalks and claws are marked with numerous red spots. C. tubularis and its sister species, C. verrilli, are the only hermit crabs known to show sexual dimorphism in shell choice, with males using normal marine gastropod shells, while females use shells of gastropods in the family Vermetidae, which are attached to rocks or other hard substrates.
Neolithodes is a genus of king crabs, in the family Lithodidae. They are found in all major oceans, both in high and low latitudes. Although there are records from water as shallow as 124 m (407 ft) in cold regions, most records are much deeper, typically 700–2,000 m (2,300–6,600 ft), with the deepest confirmed at 5,238 m (17,185 ft). They are fairly large to large crabs that typically are reddish in color and spiny, although the size of these spines varies depending on species.
Cryptolithodes typicus, often referred to as the butterfly crab or the turtle crab, is a species of lithodid crustacean native to coastal regions of the northeastern Pacific Ocean, ranging from Amchitka Island, Alaska to Santa Rosa Island, California.
Albunea carabus is a rare species of "sand crab" or "mole crab" in the family Albuneidae. It lives in shallow, turbulent waters in sandy areas of the tropical eastern Atlantic Ocean and the Mediterranean Sea.
Neolithodes grimaldii, the porcupine crab, is a species of king crab in the family Lithodidae. This large red crab is found in cold deep waters in the North Atlantic and often caught as a bycatch in fisheries for Greenland turbot. As suggested by its common name, the carapace and legs are covered in long spines.
Lithodes turkayi is a species of king crab.
Lithodes manningi is a species of king crab.
Lithodes confundens is a species of king crab.
