No, otters are not marsupials. They belong to the family Mustelidae, which includes other animals like weasels, badgers, and ferrets. Otters are classified as mammals, but they do not possess the characteristics that define marsupials.
Marsupials are a distinct group of mammals primarily found in Australia and nearby islands. They are characterized by their unique reproductive system, where females typically carry and nurse their young in a pouch. Examples of marsupials include kangaroos, koalas, and opossums.
In contrast, otters give birth to fully developed young without the need for a pouch. After birth, otter pups are cared for by their mothers but are nursed without being kept in a pouch, which is a key difference that separates them from marsupials.