The traditional practice of using (by now) endangered species is controversial within TCM. Modern Materia Medicas such as Bensky, Clavey and Stoger's comprehensive Chinese herbal text discuss substances derived from endangered species in an appendix, emphasizing alternatives. Poachers supply the black market with such substances, including tiger penis and rhinoceros horn. The black market in rhinoceros horn has reduced the world's rhino population by more than 90 percent over the past 40 years. Concerns have also arisen over the use of turtle plastron and seahorses. TCM recognizes bear bile as a medicinal. In 1988, the Chinese Ministry of Health started controlling bile production, which previously used bears killed before winter. Now bears are fitted with a sort of permanent catheter, which is more profitable than killing the bears. More than 12,000 asiatic black bears are held in "bear farms", where they suffer cruel conditions while being held in tiny cages. The catheter leads through a permanent hole in the abdomen directly to the gall bladder, which can cause severe pain. Increased international attention has mostly stopped the use of bile outside of China; gallbladders from butchered cattle (niu dan / / ) are recommended as a substitute for this ingredient. An endangered species is a population of organisms which is facing a high risk of b
coming extinct because it is either few in numbers, or threatened by changing environmental or predation parameters. The International Union for Conservation of Nature (IUCN) has calculated the percentage of endangered species. Many nations have laws offering protection to conservation reliant species: for example, forbidding hunting, restricting land development or creating preserves. A black market or underground economy is the market in which illegal goods are traded. Due to the nature of the goods traded, the market itself is forced to operate outside the formal economy, supported by the established state power. Typically the totality of such activity is referred to with the definite article as a complement to the official economies, by market for such goods and services, e.g. "the black market in bush meat" or the state jurisdiction "the black market in China". The black market is distinct from the grey market, in which commodities are distributed through channels which, while legal, are unofficial, unauthorized, or unintended by the original manufacturer, and the white market, the legal market for goods and services. Worldwide, the underground economy is estimated to have provided 1.8 billion jobs. Seahorse is the title given to forty-seven species of marine fish in the genus Hippocampus. "Hippocampus" comes from the Ancient Greek hippos meaning "horse" and kampos meaning "sea monster".