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Portal:Cetaceans

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A Sperm Whale fluke

Cetacea (/sɪˈtʃə/) are a widely distributed and diverse clade of aquatic mammals that today consists of the whales, dolphins, and porpoises. Cetaceans are carnivorous and finned. Most species live in the sea, some in rivers. The name is derived from the Latin cetus "whale", itself from the Greek κῆτος kētos "huge fish".

There are around 89 extant species, which are divided into two groups or parvorders, the Odontoceti or toothed whales, a group of more than 70 species that includes the dolphins, porpoises, belugas, narwhals, sperm and beaked whales, and the Mysticeti or baleen whales, of which there are now 15 species. The extinct ancestors of modern whales are the Archaeoceti.

While cetaceans were historically thought to have descended from mesonychids, molecular evidence supports them as a relative of Artiodactyls (even-toed ungulates). Cetaceans belong to the order Cetartiodactyla (formed by combining Cetacea + Artiodactyla) and their closest living relatives are hippopotamuses and other hoofed mammals (camels, pigs, and ruminants), having diverged about 50 million years ago.

Cetaceans range in size from the 1 m (3 ft 3 in) and 50 kg (110 lb) Maui's dolphin to the 29.9 m (98 ft) and 173,000 kg (381,000 lb) blue whale, which is also the largest animal ever known to have existed. Several species exhibit sexual dimorphism. They have streamlined bodies and two (external) limbs that are modified into flippers. Though not as flexible or agile as seals, cetaceans can swim very quickly, with the killer whale able to travel at 56 kilometres per hour (35 mph) in short bursts and the fin whale able to cruise at 48 kilometres per hour (30 mph). Dolphins are able to make very tight turns while swimming at high speeds. The hindlimbs of cetaceans are internal, and are thought to be vestigial. Baleen whales have short hairs on their mouth, unlike the toothed whales. Cetaceans have well-developed senses—their eyesight and hearing are adapted for both air and water, and baleen whales have a tactile system in their vibrissae. They have a layer of fat, or blubber, under the skin to maintain body heat in cold water. Some species are well adapted for diving to great depths. Read more...

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Humpback Whale underwater shot.jpg

The Humpback Whale (Megaptera novaeangliae) is a mammal which belongs to the baleen whale suborder. It is a large whale: an adult usually ranges between 12–16 m (40–50 ft) long and weighs approximately 36,000 kg (79,000 pounds), or 36 tonnes (40 short tons); females, on average, are larger than males. It is well known for its breaching (leaping out of the water), its unusually long front fins, and its complex whale song. The Humpback Whale lives in oceans and seas around the world, and is regularly sought out by whale-watchers. The Humpback Whale is found in all the major oceans, in a wide band running from the Antarctic ice edge to 65° N latitude. It is a migratory species, spending its summers in cooler, high-latitude waters, but mating and calving in tropical and sub-tropical waters.

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Cetaceans News

2014

January

The clymene dolphin (Stenella clymene) became the first confirmed naturally occurring hybrid marine mammal species when DNA analysis showed it to be descended from the spinner dolphin and the striped dolphin. [1]

2009

February

  • 10 February - Filipino fishermen have rescued around 200 melon-headed whales which were stranded in shallow waters off the coast of Bataan. Only three dolphins were reported to have died. more

January

2008

September

August

  • 26 August - Findings from the controversial Japanese whaling research program suggest that a loss of Antarctic sea ice due to increased temperatures has lowered whales' food supply, causing an overall decline in blubber. Read more...
  • 12 August - IUCN changes the conservation status of the Humpback Whale and Southern Right Whale to "least concern" due to the species' recovery. Read more...
  • 1 August - Snubfin Dolphins are recorded on camera for the first time along the Australian coastline. Read more...

Did you know...

A Harbour Porpoise.
  • ...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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A wild Bottlenose Dolphin breaching
Photo credit: NASA Kennedy Space Center

A bottlenose dolphin surfs the wake of a research boat on the Banana River - near the Kennedy Space Center

The Bottlenose Dolphin (Tursiops truncatus) is the most common and well-known dolphin species. It inhabits warm and temperate seas worldwide and may be found in all but the Arctic and the Antarctic Oceans.

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The content you are reading was created by Wikipedia volunteers. See the WikiProject Cetaceans for more.

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See also Wikispecies, a Wikimedia project dedicated to the classification of species.

Cetacean articles

Whale species

Andrews' Beaked WhaleBalaenoptera omuraiBelugaBlainville's Beaked WhaleBlue Whale Cscr-featured.svgBottlenose WhaleBowhead WhaleBryde's WhaleCuvier's Beaked WhaleDwarf Sperm WhaleFin Whale Cscr-featured.svgGervais' Beaked WhaleGiant beaked whaleGinkgo-toothed Beaked WhaleGray WhaleGray's Beaked WhaleHector's Beaked WhaleHubbs' Beaked WhaleHumpback Whale Cscr-featured.svgLayard's Beaked WhaleLongman's Beaked WhaleMelon-headed WhaleMinke WhaleNarwhalPerrin's Beaked WhalePygmy Beaked WhalePygmy Killer WhalePygmy Right WhalePygmy Sperm WhaleRight Whale Cscr-featured.svgSei Whale Cscr-featured.svgShepherd's Beaked WhaleSowerby's Beaked WhaleSpade Toothed WhaleSperm Whale Symbol support vote.svgStejneger's Beaked WhaleTrue's Beaked Whale

Dolphin species

Atlantic Spotted DolphinAtlantic White-sided DolphinAustralian Snubfin DolphinBaijiBotoChilean DolphinClymene DolphinCommerson's DolphinCommon Bottlenose DolphinDusky Dolphin Symbol support vote.svgFalse Killer WhaleFraser's DolphinGanges and Indus River DolphinHeaviside's DolphinHector's DolphinHourglass DolphinHumpback dolphinIndo-Pacific Bottlenose DolphinIrrawaddy DolphinKiller Whale Cscr-featured.svgLa Plata DolphinLong-beaked Common DolphinLong-finned pilot whalePacific White-sided DolphinPantropical Spotted DolphinPeale's DolphinPygmy Killer WhaleRight whale dolphinRisso's DolphinRough-toothed DolphinShort-beaked Common DolphinShort-finned pilot whaleSpinner DolphinStriped DolphinTucuxiWhite-beaked Dolphin

Porpoise species

Burmeister's PorpoiseDall's PorpoiseFinless PorpoiseHarbour PorpoiseSpectacled PorpoiseVaquita

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Aboriginal whalingAmbergrisAnimal echolocationArchaeocetiBaleenBaleen whaleBeached whaleBeaked WhaleBlowhole (biology)BlubberBottlenose dolphin Symbol support vote.svgCallosityCephalorhynchusCetaceaCetacean intelligenceCetologyCetology of Moby-DickCommon dolphinCumberland Sound BelugaDolphinDolphinarium Symbol support vote.svgDolphin drive hunting Symbol support vote.svgEvolution of cetaceansExploding whaleHarpoonHistory of whalingHuman–animal communicationInstitute of Cetacean ResearchInternational Whaling CommissionLagenorhynchusMelon (whale)Mesoplodont WhaleMilitary dolphinMoby-DickMocha DickMonodontidaeOceanic dolphinOrcaellaPilot Whale Symbol support vote.svgPorpoiseRiver dolphinRiver Thames WhaleRorqualsSperm whale familySperm whalingSpermacetiStenellaTay WhaleThe Marine Mammal CenterToothed WhaleU.S. Navy Marine Mammal ProgramWhale Symbol support vote.svgWhalingWhale and Dolphin Conservation SocietyWhale surfacing behaviourWhale oilWhale louseWhale songWhale watchingWolphin

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  1. ^ http://news.nationalgeographic.com/news/2014/01/140111-hybrid-dolphin-species-ocean-animal-science/
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