According to data from the International Union for Conservation of Nature (IUCN), 42,108, or about 28 per cent, of the 150,388 species assessed worldwide are under threat of extinction. According to IUCN's Red List of species threatened with extinction, 41 per cent of amphibians, 37 per cent of sharks and rays, 36 per cent of coral reefs, 28 per cent of crustaceans, 27 per cent of mammals, 21 per cent of reptiles and 13 per cent of bird species that can live both on land and in water are under threat. It was pointed out that 58 per cent of sharks and rays among the 73 cartilaginous fish species living in the Mediterranean are under the threat of extinction and that most of these creatures may disappear in a short time.