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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Humpback Whales blow a curtain of bubbles around their prey and then lunge through them with their mouths open. The Humpbacks strain the tiny creatures, called krill, through the baleen in their mouths.
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More did you know...
- ...that while the main predators of the Harbour Porpoise are Great white sharks and Orcas, Bottlenose Dolphins have been witnessed attacking and killing porpoises in response to a lessing food supply.
- ...Aboriginal whalers are permitted to hunt cetaceans, despite the IWC's memorandum on commercial hunting.
- ...the melon is an oval shaped oily, fatty lump of tissue found at the centre of the forehead of most dolphins and toothed whales, located between the blowhole and the end of the head.
- ...the Spinner Dolphin is so called because of its acrobatic displays in which they will spin longitudinally along their axis as they leap through the air.
- ...that the Tay Whale was a Humpback whale unlucky enough to be spotted near Dundee, Scotland, then the UK's premier whaling port, in early December, 1883.
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Did you know (auto-generated)
- ... that one of the first researchers to propose dolphin-assisted therapy for humans later renounced it?
- ... that the South Asian river dolphin is nearly blind and relies on echolocation for navigation?
- ... 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 one can swim with humpback whales in the Niue Nukutuluea Multiple-Use Marine Park?
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