Portal:Cetaceans
The Cetaceans Portal
Cetacea (/sɪˈteɪʃə/; from Latin cetus 'whale', from Ancient Greek κῆτος (kêtos) 'huge fish, sea monster') is an infraorder of aquatic mammals belonging to the order Artiodactyla that includes whales, dolphins and porpoises. Key characteristics are their fully aquatic lifestyle, streamlined body shape, often large size and exclusively carnivorous diet. They propel themselves through the water with powerful up-and-down movement of their tail which ends in a paddle-like fluke, using their flipper-shaped forelimbs to maneuver.
While the majority of cetaceans live in marine environments, a small number reside solely in brackish water or fresh water. Having a cosmopolitan distribution, they can be found in some rivers and all of Earth's oceans, and many species inhabit vast ranges where they migrate with the changing of the seasons.
Cetaceans are famous for their high intelligence, complex social behaviour, and the enormous size of some of the group's members. For example, the blue whale reaches a maximum confirmed length of 29.9 meters (98 feet) and a weight of 173 tonnes (190 short tons), making it the largest animal ever known to have existed.
There are approximately 89 living species split into two parvorders: Odontoceti or toothed whales (containing porpoises, dolphins, other predatory whales like the beluga and the sperm whale, and the poorly understood beaked whales) and the filter feeding Mysticeti or baleen whales (which includes species like the blue whale, the humpback whale and the bowhead whale). Despite their highly modified bodies and carnivorous lifestyle, genetic and fossil evidence places cetaceans as nested within even-toed ungulates, most closely related to hippopotamus within the clade Whippomorpha. (Full article...)
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A Blue whale skeleton, outside the Long Marine Laboratory at the University of California, Santa Cruz.
Blue Whales are the largest animal ever to have existed. Hunting of Blue Whales has led to a severe decline in numbers across the globe.
More did you know...
- ...the leading cause of death in North Atlantic Right Whales is injury sustained from colliding with ships.
- ...the Spade Toothed Whale is the rarest, and probably the most poorly known large mammalian species.
- ...the ear bone in cetaceans is fused to the walls of the bone cavity where the ear bones are, making hearing in air nearly impossible. Instead sound is transmitted through their jaws and skull bones.
- ...from its discovery by John Edward Gray in 1850 until a re-assessment in 1981, the Clymene Dolphin was regarded as sub-species of the Spinner Dolphin.
- ...the Australian Snubfin Dolphin (Orcaella heinsohni) is a recently recognised species of dolphin first described in 2005.
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Did you know (auto-generated)
- ... that one can swim with humpback whales in the Niue Nukutuluea Multiple-Use Marine Park?
- ... that one of the first researchers to propose dolphin-assisted therapy for humans later renounced it?
- ... that Celia Kaye won the Golden Globe Award for Most Promising Newcomer in 1965 for her starring role in Island of the Blue Dolphins?
- ... that the South Asian river dolphin is nearly blind and relies on echolocation for navigation?
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