About Chironectes minimus (Zimmermann, 1780)
The water opossum, scientifically named Chironectes minimus, is also known locally as the yapok. It is a marsupial belonging to the family Didelphidae, and it is the only species in the monotypic genus Chironectes. This semiaquatic animal lives in and near freshwater streams and lakes, ranging from Mexico through Central and South America to Argentina. It is the most aquatic living marsupial; the lutrine opossum also has semiaquatic habits. It is the only currently living marsupial species where both sexes have a pouch. The now-extinct thylacine, commonly called the Tasmanian tiger, also had this trait. The local name "yapok" may derive from the name of the Oyapock River in French Guiana. For reproduction, water opossums mate in December. A litter of 1 to 5 young is born 12 to 14 days later in a nest. By 22 days old, the offspring start to grow fur. By around 40 days old, their eyes open, and their bodies protrude from the mother's pouch. At 48 days of age, the young opossums detach from the mother's nipples, but they still nurse and sleep with their mother.