Pygmy hippopotamus population that freely breeds in zoos around the world. Between 1970 and 1991 the population of pygmy hippos born in captivity more than doubled. The survival of the species in zoos is more certain than the survival of the species in the wild. In captivity, the pygmy hippo lives from 42 to 55 years, longer than in the wild. Since 1919, only 41 percent of pygmy hippos born in zoos have been male. While the common hippopotamus was known to Europeans since classical antiquity, the pygmy hippopotamus was unknown outside its range in West Africa until the 19th century. Due
Longnose pygmy shark suggesting that it was close to the birth size. Males and females attain sexual maturity at under long respectively. Only six specimens of the longnose pygmy shark are known to science. Its small size and oceanic habits appear to preclude its capture by most fisheries. Coupled with its wide distribution, this species does not seem threatened by human activity and has been listed under Least Concern by the International Union for Conservation of Nature (IUCN). Longnose pygmy shark The longnose pygmy shark ("Heteroscymnoides marleyi") is a rare species of dogfish shark in the family Dalatiidae and the only member its