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
Pygmy corydoras pygmy, in its scientific name, "Corydoras pygmaeus". The common names for the species are "pygmy catfish" and "pygmy corydoras". A species of Corydoras with a similar appearance, "Corydoras hastatus" was described in the 1880s, and many specimens that were described as "Corydoras hastatus" between the 1920s and 1950s were subsequently found to be misidentified specimens of the pygmy corydoras. In older literature, the pygmy corydoras is frequently mislabeled because "Corydoras hastatus" was the only miniature Corydoras species known at the time. The pygmy corydoras is a silver-colored fish, with an unbroken black line that runs horizontally along the center of