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''Gnathostoma spinigerum'' is a parasitic nematode that causes gnathostomiasis in humans, also known as its clinical manifestations are ''creeping eruption'', ''larva migrans'', ''Yangtze edema'', ''Choko-Fuschu Tua chid'' and ''wandering swelling''. Gnathostomiasis in animals can be serious, and even fatal. The first described case of gnathostomiasis was in a young tiger that died in the London Zoo in 1835. The larval nematode is acquired by eating raw or undercooked fish and meat. ''G. spinigerum'' has a multi-host life history. The eggs hatch in fresh water and the larvae are eaten by water fleas of the genus ''Cyclops''. The water fleas are in turn eaten by small fish. Eventually, the larvae end up in the stomachs of carnivores, usually cats and dogs. The larva bores through the stomach wall and migrates around in the host's body for about three months before returning to the stomach and attaching itself in the gastric mucosa. It then takes another six months to mature. The eggs are carried in the host's feces, and if they reach fresh water the cycle begins again. As humans are not a normal host for the larva, they do not mature in humans, but can cause various degrees of damage, depending on where the larva wanders in the body. ==Description== This species grows to a length of 11 to 54 mm (0.43 to 2.13 in). Species within the genus ''Gnathostoma'' are recognized by a bulbous head with a pair of lateral lips surrounding a mouth on the longitudinal axis. The cephalic region is covered by transverse rows of cuticular spines. Internally, the head is divided into four glandular cervical sacs that attach near the esophagus, as well as four hollow spaces called ballonets, each being continuous with a cervical sac via a central canal.〔Barnes, R. 1987. Invertebrate Zoology. Orlando, Florida: Dryden Press〕 The body is typically pink and is also covered anteriorly with circles of flat spines, which become sparser and single-tipped further toward the end. Behind a bare region that constitutes roughly half of the body length, many small spines can be found on the posterior tip. the four species gnathostomiasis--''G. doloresi'', ''G. hispidum'', ''G. nipponicum'', and ''G. spinigerum'' can cause human –these species are differences in these external appearance and third larvae stage which is helpful for identification.〔Maleewong, W., P. Intapan, J. Khempila. 1995. Gnathostoma spinigerum: growth and development of third-stage larvae in vitro. The Journal of Parasitology v. 81 (Oct. '95) p. 800-3, 81: 800-803〕 As a nematode, ''Gnathostoma spinigerum'' has cylindrical, a cuticle layer with three main outer layers made of collagen and other compounds. The outer layers are non-cellular and are secreted by the epidermis. The cuticle layer protects the nematodes so they can invade the digestive tracts of animals.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Gnathostoma spinigerum」の詳細全文を読む スポンサード リンク
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