The Japanese spider crab, Macrocheira kaempferi, is the largest living arthropod; fully grown it can reach a leg span of almost 4 m (13 feet), a body size of up to 37 cm (15 inches) and a weight of up to 20 kg (44 pounds). The crab's natural habitat is on the bottom of the Pacific Ocean (some 300–400 m deep) around Japan, where it feeds on dead animals and shellfish. It is believed to have a life expectancy of up to 100 years. Download high resolution version (2048x1536, 700 KB)Spider crab at the Kaiyukan Aquarium in Osaka, Japan. ... Scientific classification or biological classification is how biologists group and categorize extinct and living species of organisms. ... Phyla Subregnum Parazoa Porifera (sponges) Subregnum Agnotozoa Placozoa (trichoplax) Orthonectida (orthonectids) Rhombozoa (dicyemids) Subregnum Eumetazoa Radiata (unranked) (radial symmetry) Ctenophora (comb jellies) Cnidaria (coral, jellyfish, anemones) Bilateria (unranked) (bilateral symmetry) Acoelomorpha (basal) Myxozoa (slime animals) Superphylum Deuterostomia (blastopore becomes anus) Chordata (vertebrates, etc. ... Subphyla and Classes Subphylum Trilobitomorpha Trilobita - trilobites (extinct) Subphylum Chelicerata Arachnida - spiders,scorpions, etc. ... Classes & Subclasses Branchiopoda Phyllopoda Sarsostraca Remipedia Cephalocarida Maxillopoda Thecostraca Tantulocarida Branchiura Pentastomida Mystacocarida Copepoda Ostracoda Myodocopa Podocopa Malacostraca Phyllocarida Hoplocarida Eumalacostraca The crustaceans (Crustacea) are a large group of arthropods (55,000 species), usually treated as a subphylum [1]. They include organisms such as lobsters, crabs, shrimp and barnacles. ... Subclasses Eumalacostraca Hoplocarida Phyllocarida See text for orders. ... Suborders and Infraorders Dendrobranchiata Pleocyemata Caridea Stenopodidea Reptantia, comprising: Eryonoidea Achelata Astacidea Glypheidea Thalassinidea Anomala Brachyura The decapods or Decapoda are a group of crustaceans within the class Malacostraca, including many familiar groups of crustaceans, such as crabs, lobsters and shrimp, but also some families that are less well known. ... Superfamilies Dromiacea Homolodromioidea Dromioidea Homoloidea Eubrachyura Raninoidea Cyclodorippoidea Dorippoidea Calappoidea Leucosioidea Majoidea Hymenosomatoidea Parthenopoidea Retroplumoidea Cancroidea Portunoidea Bythograeoidea Xanthoidea Bellioidea Potamoidea Pseudothelphusoidea Gecarcinucoidea Cryptochiroidea Pinnotheroidea * Ocypodoidea * Grapsoidea * An asterisk (*) marks the crabs included in the clade Thoracotremata. ... Genera Cyclax Eurynome Lissa Macropodia Maja Schizophroida Schizophrys Thacanophyrys Majidae is a family of crabs, comprising around 700 marine species with a carapace that is longer than it is broad, and which forms a point at the front. ... In biology, binomial nomenclature is the formal method of naming species. ... Coenraad Jacob Temminck (March 31, 1778 - January 30, 1858) was a Dutch aristocrat and zoologist. ... Subphyla and Classes Subphylum Trilobitomorpha Trilobita - trilobites (extinct) Subphylum Chelicerata Arachnida - spiders,scorpions, etc. ... The metre, or meter (US), is a measure of length. ... This article is about a foot as a unit of length. ... A centimetre (US: centimeter) is a factor of the SI unit of length: there are one hundred centimeters in the base unit of measure, the metre. ... Mid-19th century tool for converting between different standards of the inch An inch is an Imperial and U.S. customary unit of length. ... The international prototype, made of platinum-iridium, which is kept at the BIPM under conditions specified by the 1st CGPM in 1889. ... The pound is the name of a number of units of mass, all in the range of 300 to 600 grams. ... Habitat (from the Latin for it inhabits) is the place where a particular species lives and grows. ... Cooked mussels Shellfish is a term used to describe shelled molluscs and crustaceans used as food. ... World map of life expectancy Life expectancy is a statistical measure defined as the expected (mean) survival. ...

It is a particularly old species of crab, and it is often referred to as a living fossil. Currently, this is the only species of the genus Macrocheira, but there have been two reports of other fossil specimens. Living fossil is a term for any living species (or clade) of organism which closely resembles species otherwise only known from fossils and has no close living relatives. ... An ammonite fossil Fossils (from Latin fossus, literally having been dug up) are the mineralized or otherwise preserved remains or traces (such as footprints) of animals, plants, and other organisms. ...

Physical characteristics

The crab has an orange body, but it has white spots on its thin legs. The claws of male specimens become longer than its legs, and a large male's claws, when opened, can widen to 3 metres. Unconfirmed reports suggest a maximum spread of nearly 7 metres ^[1]. The width of the oval-shaped and vertically rounded shell can reach up to 30 cm, and can be up to 40 cm long. An insect leg The arthropod leg is a form of jointed appendage of arthropods, usually used for walking. ...

Its compound eyes are situated on the front, and two thorns stick out between them. Younger specimens feature hair and thorns on the shell, and their frontal horns are longer, but these gradually atrophy as they grow older. Compound eye of a dragonfly Compound eye of Antarctic krill as imaged by an electron microscope A compound eye is a visual organ found in certain arthropods such as insects and crustaceans. ...

Natural habitat and human impact

The Japanese spider crab's habitat is limited to the Pacific side of the Japanese archipelago. They often live in the seabed at depths of 150–800 m, but are found most prominently in depths of 200–300 m. In spring, they can often be found laying eggs in waters as shallow as 50 m. View of the Pacific Ocean from Oregon. ...

The Japanese spider crab is caught using small trawling nets, and is often eaten salted and steamed. It is caught in the Sagami, Suruga, and Tosa bays and also around the Izu Islands. Catching of the crab is forbidden during the spring, when it lays its eggs. Sagami Bay (相模湾, Sagami-wan), also known as the Sagami Gulf or Sagami Sea, lies south of Kanagawa Prefecture in Honshu, central Japan, with the Miura Peninsula to its east and the Izu Peninsula to its west. ... Suruga Bay (Suruga-wan) is a bay on the Pacific coast of Honshu, Japan, in Shizuoka Prefecture. ... Location Map of Islands The Izu Islands (伊豆諸島) are a group of volcanic islands stretching south and east from the Izu Peninsula of Honshu, Japan. ...

It is considered a specialty around Suruga Bay, but numbers of the crab have diminished over recent years, and there are efforts to protect them. In Wakayama Prefecture, the crabs are caught when they move to shallower waters in the spring. Wakayama Prefecture ) is part of the Kii Peninsula in the Kinki region on Honshu island, Japan. ...

The Japanese spider crab is also used for research and ornamental purposes. It has a gentle disposition and is often reared in aquaria. For other uses, see Aquarium (disambiguation). ...

See also

• Portly spider crab

Binomial name Libinia emarginata Leach, 1815 The Portly spider crab (Libinia emarginata) is a species of crab found in estuarine habitats on the east coast of North America from Nova Scotia to the Gulf of Mexico. ...

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