Cetaceans | Cetacea
Cetacean are an order of aquatic mammals, such as dolphins and whales. Most Cetacean live in the ocean, although there are a few species of dolphins that live in rivers in Asia and South America. Cetacean have specially developed hearing and sight to work underwater, and some species of Cetacean use echolocation. Cetacean are found worldwide, but typically prefer colder waters in the Northern and Southern hemispheres. Cetacean typically feed on fish and marine invertebrate, but some, such as the Killer Whale, feed on large mammals or birds, as well. Cetaceans have been hunted for their meat, oil, blubber, and to be kept in captivity to be exploited for entertainment.
The 3 groups of organisms that are considered cetaceans are whales, dolphins and porpoises. The 3 groups are made of 89 species in total. The cetacean order is further divided into 2 groups: toothed whales (odontocetes) that includes over 73 species and baleen whales (mysticetes) that is made up of 11 species.
All species of cetaceans are carnivores. A cetaceans’ diet depends on the species, but most cetaceans feed on mostly fish, and marine invertebrates. Some like the killer whale, feed on large mammals and birds like penguins or seals. Baleen whales usually eat mollusks, copepods, krill, small fish, and squid.
Cetaceans can be found in all climates and all oceans of the world ranging from the coldest waters to tropical waters. Some species live only in specific areas, like the southern right whale dolphin and hourglass dolphin that only inhabit the Antarctic Ocean. Some species of whales migrate between seasonal habitats like the gray whale.