Cetaceans [Cetacea]
Description
Cetacea includes aquatic mammals known as whales, dolphins, and porpoises. This order is characterized by their fully aquatic lifestyle, streamlined bodies, and absence of hind limbs. They have a thick layer of blubber for insulation, and their forelimbs are modified into flippers. Cetaceans are found in all the world's oceans, from the Arctic and Antarctic to tropical seas. They are divided into two suborders: the baleen whales (Mysticeti), which filter feed by trapping tiny organisms in their baleen plates, and the toothed whales (Odontoceti), which include dolphins and porpoises, known for their echolocation abilities.