Bombyx mori silkworms for the production of raw silk, has been under way for at least 5,000 years in China, from where it spread to India, Korea, Japan, and the West. The silkworm was domesticated from the wild silkmoth "Bombyx mandarina", which has a range from northern India to northern China, Korea, Japan, and the far eastern regions of Russia. The domesticated silkworm derives from Chinese rather than Japanese or Korean stock. Silkworms were unlikely to have been domestically bred before the Neolithic age. Before then, the tools to manufacture quantities of silk thread had not been developed. The domesticated "B. mori"
Crustacean larva long rostrum, and a spine on either side of the carapace; the first post-larva closely resembles the adult. Porcelain crabs have two or three larval stages, in which the rostrum and the posterior spine on the carapace are "enormously long". Hermit crabs pass through around four larval stages. The post-larva is known as the "glaucothoe", after a genus named by Henri Milne-Edwards in 1830. The glaucothoe is long in "Pagurus longicarpus", but glaucothoe larvae up to are known, and were once thought to represent animals which had failed to develop correctly. Like the preceding stages, the glaucothoe is symmetrical, and