King crabs are decapod crustaceans of the family Lithodidae that are chiefly found in deep waters and are adapted to cold environments. They are composed of two subfamilies: Lithodinae, which tend to inhabit deep waters, are globally distributed, and comprise the majority of the family's species diversity; and Hapalogastrinae, which are endemic to the North Pacific and inhabit exclusively shallow waters. King crabs superficially resemble true crabs but are generally understood to be closest to the pagurid hermit crabs. This placement of king crabs among the hermit crabs is supported by several anatomical peculiarities which are present only in king crabs and hermit crabs, making them a prominent example of carcinisation among decapods. Several species of king crabs, especially in Alaskan and southern South American waters, are targeted by commercial fisheries and have been subject to overfishing.
Cancer pagurus, commonly known as the edible crab or brown crab, is a species of crab found in the North Sea, North Atlantic Ocean, and perhaps the Mediterranean Sea. It is a robust crab of a reddish-brown colour, having an oval carapace with a characteristic "pie crust" edge and black tips to the claws. A mature adult may have a carapace width up to 25 centimetres and weigh up to 3 kilograms. C. pagurus is a nocturnal predator, targeting a range of molluscs and crustaceans. It is the subject of the largest crab fishery in Western Europe, centred on the coasts of the Ireland and Britain, with more than 60,000 tonnes caught annually.
Scylla serrata is an ecologically important species of crab found in the estuaries and mangroves of Africa, Australia, and Asia. In their most common forms, their shell colours vary from a deep, mottled green to very dark brown.
Ocypode is a genus of ghost crabs found in the sandy shores of tropical 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 scavengers and predators of small animals. The genus contains 21 species.
The Tasmanian giant crab, also known as the giant deepwater crab, giant southern crab, queen crab, or bullcrab, is a very large species of crab that resides on rocky and muddy bottoms in the oceans off Southern Australia. It is the only extant species in the genus Pseudocarcinus.
Carcinus maenas is a common littoral crab. It is known by different names around the world. In the British Isles, it is generally referred to as the shore crab, or green shore crab. In North America and South Africa, it bears the name European green crab.
Portunidae is a family of crabs which contains the swimming crabs. Its members include many well-known shoreline crabs, such as the blue crab and velvet crab. Two genera in the family are contrastingly named Scylla and Charybdis; the former contains the economically important species black crab and Scylla paramamosain.
Cancridae is a family of crabs. It comprises six extant genera, and ten exclusively fossil genera, in two subfamilies:
Decorator crabs are crabs of several different species, belonging to the superfamily Majoidea, that use materials from their environment to hide from, or ward off, predators. They decorate themselves by sticking mostly sedentary animals and plants to their bodies as camouflage, or if the attached organisms are noxious, to ward off predators through aposematism.
The Sesarmidae are a family of crabs, previously included in the Grapsidae by many authors. Several species, namely in Geosesarma, Metopaulias, and Sesarma, are true terrestrial crabs. They do not need to return to the sea even for breeding.
The coconut crab is a terrestrial species of giant hermit crab, and is also known as the robber crab or palm thief. It is the largest terrestrial arthropod known, with a weight of up to 4.1 kg (9 lb). The distance from the tip of one leg to the tip of another can be as wide as 1 m. It is found on islands across the Indian and Pacific Oceans, as far east as the Gambier Islands, Pitcairn Islands and Caroline Island and as far west as Zanzibar. While its range broadly shadows the distribution of the coconut palm, the coconut crab has been extirpated from most areas with a significant human population such as mainland Australia and Madagascar.
Glaucus is a genus of small blue pelagic sea slugs. They are aeolid nudibranchs, ranging in size from 20 to 40 mm. They feed on colonial cnidarians such as Portuguese man o' wars, blue buttons, and purple sails. They can produce painful and potentially dangerous stings when handled, as they store the venomous nematocysts of their prey. Glaucus is the only genus in the family Glaucidae. It includes five species.
Percnon is a genus of crabs in the family Percnidae. It has also been included in the family Plagusiidae as subfamily Percninae.
The Plagusiidae are a family of crabs, formerly treated as a subfamily of the family Grapsidae, but have since been considered sufficiently distinct to be a family in their own right. The family Plagusiidae includes the subfamily Plagusiinae, comprising the genera Percnon and Plagusia, which constitute a widespread group of litophilic, intertidal and subtidal crabs that are notorious for their speed and their agility.
Hypothalassia acerba is a large crab found in the muddy substrates of the deep seas off the southwestern Australian and New Zealand coasts. Australian distribution, which is correlated to depth and temperature, ranges from a latitude as far north as approximately 27° S on the west coast, southwards, then eastwards on the south coast to a longitude of at least 129° E. The species usually occurs in waters with temperatures of 13–19 °C (55–66 °F) and in depths ranging of 200–255 metres (656–837 ft) on the lower west coast and 90–200 m (300–660 ft) on the south coast. Body size is inversely related to depth of water. There are only two species in the genus Hypothalassia, and H. acerba is not the same champagne crab as the other Hypothalassia species, H. armata, which is found in Japanese waters.
Crustaceans are invertebrate animals that constitute one group of arthropods that are a part of the subphylum Crustacea, a large, diverse group of mainly aquatic arthropods including decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, opossum shrimps, amphipods and mantis shrimp. The crustacean group can be treated as a subphylum under the clade Mandibulata. It is now well accepted that the hexapods emerged deep in the Crustacean group, with the completed pan-group referred to as Pancrustacea. The three classes Cephalocarida, Branchiopoda and Remipedia are more closely related to the hexapods than they are to any of the other crustaceans.
Percnidae is a family of crabs in the superfamily Grapsoidea. Percnidae contains about six described species in one genus: Percnon.
The horsehair crab, Erimacrus isenbeckii, is a species of crab which is found mainly in the Northwest Pacific, around the Hokkaido coast in the Sea of Okhotsk and the Western Bering Sea and is an important commercial species used in Japanese cuisine. Despite the importance of the species, biological studies are usually specialized and limited. The catch for the species reached a peak in the 1950s at 27,000 tons and has decreased since, reaching 2,000 tons in 2003. Due to the commercial importance of the species, many stock enhancement programs have been utilized to help maintain a successful fishery. The species is commonly found on sandy benthic environments from shallow water to depths of up to 350 meters.
Heterocyathus is a genus of coral of the family Caryophylliidae.
Oziidae is a family of crabs in the order Decapoda. There are about 7 genera and more than 30 described species in Oziidae.
