<Li> Family Physeteridae (sperm whale), one species </Li> <Li> Family Kogiidae (pygmy and dwarf sperm whales), one genus and two species </Li> <Li> Family Monodontidae (narwhal and beluga), two genera and two species </Li> <Li> Family Ziphiidae (beaked whales), six genera and 21 species </Li>

Which marine ecosystem requires living organisms to adapt to both land and sea environments