Toothed whale 326837 224611864 2008-07-09T17:29:32Z ClockwerkMao 7332534 /* Behaviour */ {{Taxobox | name = Toothed whales | fossil_range = Latest [[Eocene]] - Recent | image = Bottlenose Dolphin KSC04pd0178.jpg | image_width = 250px | image_caption = [[Bottlenose Dolphin]] | regnum = [[Animal]]ia | phylum = [[Chordate|Chordata]] | classis = [[Mammal]]ia | ordo = [[Cetacea]] | subordo = '''Odontoceti''' | subordo_authority = Flower, 1869 | subdivision_ranks = [[Family (biology)|Families]] | subdivision = See text. | diversity = Around 73; see [[List of cetaceans]] or [[Toothed whale#Taxonomy|below]]. | diversity_link = List of cetaceans }} {{cetaceaportal}} The '''toothed whales''' ([[systematic name]] '''Odontoceti''') form a [[suborder]] of the [[cetacean]]s, including sperm whales, beaked whales, killer whales, dolphins, and others. As the name suggests, the suborder is characterized by having [[teeth]], rather than [[baleen]] as do animals in the other suborder of cetaceans, [[Mysticeti]]. However, fossils indicate that early Baleen whales had teeth as well before evolving baleen, so defining the Odontoceti on teeth alone is problematic, and paleontologists have instead identified other features uniting fossil and modern odontocetes that are not shared by mysticetes. Toothed whales are active hunters, feeding on fish, squid, and in some cases marine mammals. == Anatomy == Toothed whales have a single [[blowhole (biology)|blowhole]] on the top of the head (while the baleen whales possess two of them). The [[nostril]]s are not fused; one of them has become dominant over the other. As an adaptation for their [[echolocation]], toothed whale skulls have become asymmetric. Their brains are relatively big, although real growth didn't occur before their echolocation started to evolve. Toothed whales' brains have a poor connection between the two hemispheres and an organ called a melon on their heads is used as a lens to focus sound waves. Vocal cords are not present; their sounds are produced in the blowhole system instead. Toothed whales have lost their sense of smell, as well as their saliva glands. Except for the [[Sperm Whale]], most toothed whales are smaller than the [[baleen whale]]s. The teeth differ considerably between the species. They may be numerous, with some [[dolphin]]s bearing over 100 teeth in their jaws. At the other extreme are the [[Narwhal]] with its single long tusk and the almost toothless [[beaked whales]] with bizarre teeth only in males. Not all species are believed to use their teeth for feeding. For instance, the Sperm Whale likely uses its teeth for aggression and showmanship. == Behaviour == === Vocalizations === Vocalizations are of great importance to toothed whales. While many species also maintain a broad variety of calls to communicate, all species investigated so far use short click sounds for purposes of [[animal echolocation|echolocation]]. [[Sperm whales]] use low frequencies (a few to perhaps 50 kHz), while other employ more narrow band high frequency sounds ([[porpoises]], [[Cephalorhynchus]] species like [[Hector's dolphin]]). Most dolphin species use very broad band clicks. === Movement === Most toothed whales swim rapidly. The smaller species occasionally ride waves, such as the bow waves of ships. [[Dolphin]]s can be frequently encountered this way. They are also famous for their acrobatic breaching from the water, e.g. the [[Spinner Dolphin]]. == Human impact == The [[Sperm Whale]] has been hunted commercially for a long time (''see'' [[whaling]]). While small whales like the [[Pilot Whale]] today are still being pursued, the main threat for most species is accidental capture in fishing nets. Keeping small whales (mostly [[Bottlenose Dolphin]]s, [[Orca]]s, or [[Beluga]]s) in captivity is a great attraction for ocean parks and zoos. However, it is controversial because of the marine mammals' need for large spaces. == Taxonomy == *'''ORDER [[Cetacea|CETACEA]]''' <div style="padding-left:20px"> *{{Odontoceti taxonomy}} </div> {{Cetacea}} [[Category:Toothed whales|*]] [[zh-min-nan:Khí-keng]] [[ca:Odontocet]] [[cs:Ozubení]] [[da:Tandhvaler]] [[de:Zahnwale]] [[es:Odontoceti]] [[eo:Dentocetacoj]] [[fr:Odontoceti]] [[ko:이빨고래아목]] [[hr:Kitovi zubani]] [[it:Odontoceti]] [[he:לווייתני שיניים]] [[ka:კბილიანი ვეშაპები]] [[lt:Dantytieji banginiai]] [[hu:Fogascetek]] [[nl:Tandwalvissen]] [[ja:ハクジラ亜目]] [[no:Tannhvaler]] [[nn:Tannkvalar]] [[oc:Odontoceti]] [[pl:Zębowce]] [[pt:Odontoceti]] [[ru:Зубатые киты]] [[sk:Bezkosticovce]] [[fi:Hammasvalaat]] [[sv:Tandvalar]] [[zh-yue:齒鯨亞目]] [[zh:齿鲸]]