Портал:Китовые

Темы портала: Деятельность; Культура; География; Здоровье; История; Математика; Природа; Люди; Философия; Религия; Общество; Технологии; Случайный портал

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Портал китообразных

П:CET

Китообразные ( Cetacea , / sɪ ˈ t eɪ ʃ ə / ; от лат. cetus « кит », от др.-греч. κῆτος ( kêtos ) « огромная рыба , морское чудовище ») — инфраотряд водных млекопитающих, принадлежащих к отряду парнокопытных , в который входят киты , дельфины и морские свиньи . Ключевыми характеристиками являются их полностью водный образ жизни, обтекаемая форма тела, часто крупные размеры и исключительно плотоядная диета. Они продвигаются по воде мощными движениями вверх-вниз своего хвоста, который заканчивается веслообразным хвостовым плавником, используя свои передние конечности в форме ласт для маневрирования.

В то время как большинство китообразных обитают в морской среде, небольшое число обитает исключительно в солоноватой или пресной воде . Имея космополитное распространение , их можно найти в некоторых реках и во всех океанах Земли, и многие виды населяют обширные ареалы, куда они мигрируют со сменой сезонов.

Китообразные славятся своим высоким интеллектом , сложным социальным поведением и огромными размерами некоторых членов группы. Например, синий кит достигает максимальной подтвержденной длины 29,9 метров (98 футов) и веса 173 тонны (190 коротких тонн), что делает его крупнейшим животным, когда-либо существовавшим.

Существует около 89 ныне живущих видов, разделенных на два парвотряда : зубатые киты (включая морских свиней , дельфинов , других хищных китов, таких как белуха и кашалот , а также плохо изученных клюворылых китов ) и фильтрующие киты Mysticeti или усатые киты (включая такие виды, как синий кит , горбатый кит и гренландский кит ). Несмотря на их сильно измененные тела и плотоядный образ жизни, генетические и ископаемые данные помещают китообразных в гнездо среди парнокопытных , наиболее тесно связанных с бегемотами в пределах клады Whippomorpha . ( Полная статья... )

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Здесь представлены статьи категорий «хорошо» и «избранное» , которые соответствуют основным высоким редакционным стандартам.

Image 1

Криптолепас рахианекси

Китовые ракушки — этовид желудевых рачков , принадлежащих к семейству Coronulidae . Обычно они прикрепляются к усатым китам , а иногда поселяются на зубатых китах . Китовые ракушки произошли от черепаховых рачков около трех миллионов лет назад .

Китовые ракушки пассивно фильтруют пищу, используя щупальцеобразные усики , пока хозяин плывет по воде. Такое расположение обычно считается комменсальным, поскольку оно осуществляется без каких-либо затрат или выгод для хозяина. Однако некоторые киты могут использовать ракушек в качестве защитной брони или для нанесения большего урона во время драки, что делает отношения взаимными , где обе стороны получают выгоду; в качестве альтернативы, некоторые виды могут просто увеличивать сопротивление , которое хозяин испытывает во время плавания, делая ракушек паразитами . ( Полная статья... )
Image 2
The anatomist John Struthers (at left, in top hat) with the Tay Whale at John Woods' yard, Dundee, 1884, photographed by George Washington Wilson

The Tay Whale, known locally as the Monster, was a humpback whale that swam into the Firth of Tay of eastern Scotland in 1883. It was harpooned in a hunt, but escaped, and was found floating dead off Stonehaven a week later. It was towed into Dundee by a showman, John Woods, and exhibited on a train tour of Scotland and England.

The Regius Professor of Anatomy at Aberdeen University, John Struthers dissected the whale, much of the time in public with a military band playing in the background, organised by Woods. The decomposing whale made Woods a great deal of money, and Struthers famous. (Full article...)
Image 3

Cast of skull at the Natural History Museum of the University of Pisa

Livyatan is an extinct genus of macroraptorial sperm whale containing one known species: L. melvillei. The genus name was inspired by the biblical sea monster Leviathan, and the species name by Herman Melville, the author of the famous novel Moby-Dick about a white bull sperm whale. Herman Melville often referred to whales as "Leviathans" in his book. It is mainly known from the Pisco Formation of Peru during the Tortonian stage of the Miocene epoch, about 9.9–8.9 million years ago (mya); however, finds of isolated teeth from other locations such as Chile, Argentina, the United States (California), South Africa and Australia imply that either it or a close relative survived into the Pliocene, around 5 mya, and may have had a global presence. It was a member of a group of macroraptorial sperm whales (or "raptorial sperm whales") and was probably an apex predator, preying on whales, seals and so forth. Characteristically of raptorial sperm whales, Livyatan had functional, enamel-coated teeth on the upper and lower jaws, as well as several features suitable for hunting large prey.

Livyatan's total length has been estimated to be about 13.5–17.5 m (44–57 ft), almost similar to that of the modern sperm whale (Physeter macrocephalus), making it one of the largest predators known to have existed. The teeth of Livyatan measured 36.2 cm (1.19 ft), and are the largest biting teeth of any known animal, excluding tusks. It is distinguished from the other raptorial sperm whales by the basin on the skull spanning the length of the snout. The spermaceti organ contained in that basin is thought to have been used in echolocation and communication, or for ramming prey and other sperm whales. The whale may have interacted with the large extinct shark megalodon (Otodus megalodon), competing with it for a similar food source. Its extinction was probably caused by a cooling event at the end of the Miocene period causing a reduction in food populations. The geological formation where the whale has been found has also preserved a large assemblage of marine life, such as sharks and marine mammals. (Full article...)
Image 4

Artistic reconstruction

Arktocara is an extinct genus of river dolphin from the Oligocene epoch of Alaska, containing one species, A. yakataga. Having been discovered in 25-million-year-old strata near the 60th parallel north, it is perhaps the oldest-known crown toothed whale and the northmost river dolphin discovered. It was a member of the now-extinct family Allodelphinidae, along with the genera Allodelphis, Goedertius, Ninjadelphis, and Zarhinocetus. It measured approximately 2.26 or 2.28 meters (7.4 or 7.5 ft), comparable to its closest living relative, the South Asian river dolphin, which measures 2.4 meters (7.9 ft). However, the animal probably had an elongated beak and neck, so it may have been longer. The animal is known only from a partially preserved skull. Its ecology may have been similar to the modern-day Dall's porpoise, and it may have competed with contemporaneous delphinoids. Its remains were found in the Poul Creek Formation, which has also yielded several mollusk species. (Full article...)
Image 5

Granny (born c. 1936-1951 approx, died c. 2016), also known as J2, was a female orca of the J pod of southern resident orcas notable for her long life. Early estimates placed her birth in 1911, putting her at 105 years old at the time of her death. However, this estimate was later theorized to have been based on mistaken information and more recent studies put her at 65–80 years old. If she was 105, she would have been the oldest known orca at the time of her death. Granny lived in the northeast Pacific Ocean and coastal bays of Washington state and British Columbia. She was last seen on October 12, 2016, and was considered deceased by The Center for Whale Research in January 2017. (Full article...)
Image 6

Pilot whales are cetaceans belonging to the genus Globicephala. The two extant species are the long-finned pilot whale (G. melas) and the short-finned pilot whale (G. macrorhynchus). The two are not readily distinguishable at sea, and analysis of the skulls is the best way to distinguish between the species. Between the two species, they range nearly worldwide, with long-finned pilot whales living in colder waters and short-finned pilot whales living in tropical and subtropical waters. Pilot whales are among the largest of the oceanic dolphins, exceeded in size only by the orca. They and other large members of the dolphin family are also known as blackfish.

Pilot whales feed primarily on squid, but will also hunt large demersal fish such as cod and turbot. They are highly social and may remain with their birth pod throughout their lifetime. Short-finned pilot whales are one of the few non-primate mammal species in which females go through menopause, and postreproductive females continue to contribute to their pod. Pilot whales are notorious for stranding themselves on beaches, but the reason behind this is not fully understood, although marine biologists have shed light on the discovery it is due to the mammals inner ear (their principal navigational sonar) being damaged from noise-pollution in the ocean, such as from cargo ships or military exercises. The conservation status of short-finned and long-finned pilot whales has been determined to be least concern. (Full article...)
Image 7

Top (left) and underside (right) views of the skull

Kogia pusilla is an extinct species of sperm whale from the Middle Pliocene of Italy, also known as the Littleness Sperm Whale. related to the modern-day dwarf sperm whale (K. sima) and pygmy sperm whale (K. breviceps). It is known from a single skull discovered in 1877, and was considered a species of beaked whale until 1997. The skull shares many characteristics with other sperm whales, and is comparable in size to that of the dwarf sperm whale. Like the modern Kogia, it probably hunted squid in the twilight zone, and frequented continental slopes. The environment it inhabited was likely a calm, nearshore area with a combination sandy and hard-rock seafloor. K. pusilla likely died out due to the ice ages at the end of the Pliocene. (Full article...)
Image 8

The holotype and only specimen

Orcinus meyeri is a fossil species of Orcinus (killer whales) found in the Early Miocene deposits of southern Germany, known from two jaw fragments and 18 isolated teeth. It was originally described as Delphinus acutidens in 1859, but reclassified in 1873. Its validity is disputed, and it may be a synonymous with the ancient sperm whale Physeterula dubusi. It was found in the Alpine town of Stockach in the Molasse basin, which was a coastal area with strong tidal currents. (Full article...)
Image 9

The false killer whale (Pseudorca crassidens) is a species of oceanic dolphin that is the only extant representative of the genus Pseudorca. It is found in oceans worldwide but mainly in tropical regions. It was first described in 1846 as a species of porpoise based on a skull, which was revised when the first carcasses were observed in 1861. The name "false killer whale" comes from having a skull similar to the orca (Orcinus orca), or killer whale.

The false killer whale reaches a maximum length of 6 m (20 ft), though size can vary around the world. It is highly sociable, known to form pods of up to 50 members, and can also form pods with other dolphin species, such as the common bottlenose dolphin (Tursiops truncatus). It can form close bonds with other species, as well as have sexual interactions with them. But the false killer whale has also been known to eat other dolphins, though it typically eats squid and fish. It is a deep-diver; maximum known depth is 927.5 m (3,043 ft); maximum speed is ~ 29 km/h (18 mph). (Full article...)
Image 10

Reconstructed skeleton at the Natural History Museum of the University of Pisa

Ambulocetus (Latin ambulare "to walk" + cetus "whale") is a genus of early amphibious cetacean from the Kuldana Formation in Pakistan, roughly 48 or 47 million years ago during the Early Eocene (Lutetian). It contains one species, Ambulocetus natans (Latin natans "swimming"), known solely from a near-complete skeleton. Ambulocetus is among the best-studied of Eocene cetaceans, and serves as an instrumental find in the study of cetacean evolution and their transition from land to sea, as it was the first cetacean discovered to preserve a suite of adaptations consistent with an amphibious lifestyle. Ambulocetus is classified in the group Archaeoceti—the ancient forerunners of modern cetaceans whose members span the transition from land to sea—and in the family Ambulocetidae, which includes Himalayacetus and Gandakasia (also from the Eocene of the Indian subcontinent).

Ambulocetus had a narrow, streamlined body, and a long, broad snout, with eyes positioned at the very top of its head. Because of these features, it is hypothesised to have behaved much like a crocodile, waiting near the water's surface to ambush large mammals, using its powerful jaws to clamp onto and drown or thrash prey. Additionally, its ears possessed similar traits to modern cetaceans, which are specialised for hearing and detecting certain frequencies underwater, although it is unclear if Ambulocetus also used these specialised ears for hearing underwater. They may have instead been utilised for bone conduction on land, or perhaps served no function for early cetaceans. (Full article...)
Image 11

The sperm whale or cachalot (Physeter macrocephalus) is the largest of the toothed whales and the largest toothed predator. It is the only living member of the genus Physeter and one of three extant species in the sperm whale family, along with the pygmy sperm whale and dwarf sperm whale of the genus Kogia.

The sperm whale is a pelagic mammal with a worldwide range, and will migrate seasonally for feeding and breeding. Females and young males live together in groups, while mature males (bulls) live solitary lives outside of the mating season. The females cooperate to protect and nurse their young. Females give birth every four to twenty years, and care for the calves for more than a decade. A mature, healthy sperm whale has no natural predators, although calves and weakened adults are sometimes killed by pods of killer whales (orcas). (Full article...)
Image 12
Cetacea is an infraorder that comprises the 94 species of whales, dolphins, and porpoises. It is divided into toothed whales (Odontoceti) and baleen whales (Mysticeti), which diverged from each other in the Eocene some 50 million years ago (mya). Cetaceans are descended from land-dwelling hoofed mammals, and the now extinct archaeocetes represent the several transitional phases from terrestrial to completely aquatic. Historically, cetaceans were thought to have descended from the wolf-like mesonychians, but cladistic analyses confirm their placement with even-toed ungulates in the order Cetartiodactyla.

Whale populations were drastically reduced in the 20th century from intensive whaling, which lead to a moratorium on hunting by the International Whaling Commission in 1982. Smaller cetaceans are at risk of accidentally getting caught by fishing vessels using, namely, seine fishing, drift netting, or gill netting operations. (Full article...)
Image 13

The dwarf sperm whale (Kogia sima) is a sperm whale that inhabits temperate and tropical oceans worldwide, in particular continental shelves and slopes. It was first described by biologist Richard Owen in 1866, based on illustrations by naturalist Sir Walter Elliot. The species was considered to be synonymous with the pygmy sperm whale (Kogia breviceps) from 1878 until 1998. The dwarf sperm whale is a small whale, 2 to 2.7 m (6 ft 7 in to 8 ft 10 in) and 136 to 272 kg (300 to 600 lb), that has a grey coloration, square head, small jaw, and robust body. Its appearance is very similar to the pygmy sperm whale, distinguished mainly by the position of the dorsal fin on the body–nearer the middle in the dwarf sperm whale and nearer the tail in the other.

The dwarf sperm whale is a suction feeder that mainly eats squid, and does this in small pods of typically one to four members. It is preyed upon by the killer whale (Orcinus orca) and large sharks such as the great white shark (Carcharodon carcharius). When startled, the whale can eject a cloud of red-brown fluid. Most of what is known of the whale comes from beached individuals, as sightings in the ocean are rare. Many of these stranded whales died from parasitic infestations or heart failure. (Full article...)
Image 14

Southern right whale breaching

Right whales are three species of large baleen whales of the genus Eubalaena: the North Atlantic right whale (E. glacialis), the North Pacific right whale (E. japonica) and the Southern right whale (E. australis). They are classified in the family Balaenidae with the bowhead whale. Right whales have rotund bodies with arching rostrums, V-shaped blowholes and dark gray or black skin. The most distinguishing feature of a right whale is the rough patches of skin on its head, which appear white due to parasitism by whale lice. Right whales are typically 13–17 m (43–56 ft) long and weigh up to 100 short tons (91 t; 89 long tons) or more.

All three species are migratory, moving seasonally to feed or give birth. The warm equatorial waters form a barrier that isolates the northern and southern species from one another although the southern species, at least, has been known to cross the equator. In the Northern Hemisphere, right whales tend to avoid open waters and stay close to peninsulas and bays and on continental shelves, as these areas offer greater shelter and an abundance of their preferred foods. In the Southern Hemisphere, right whales feed far offshore in summer, but a large portion of the population occur in near-shore waters in winter. Right whales feed mainly on copepods but also consume krill and pteropods. They may forage the surface, underwater or even the ocean bottom. During courtship, males gather into large groups to compete for a single female, suggesting that sperm competition is an important factor in mating behavior. Gestation tends to last a year, and calves are weaned at eight months old. (Full article...)
Image 15

Holotype skull of A. deinodon

Acrophyseter is a genus of extinct sperm whale that lived in the Late Miocene off the coast of what is now Peru. The genus comprises two species: A. deinodon and A. robustus. It is part of a group of macroraptorial sperm whales that all share several features for hunting large prey, such as deeply rooted and thick teeth. Acrophyseter measured 4–4.5 metres (13–15 ft) in length, making it the smallest macroraptorial sperm whale currently known. Because of its short pointed snout and strongly curved front teeth, it probably fed on the large marine vertebrates of its time, such as seals and other whales. (Full article...)

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Выбранная фотография

Фото предоставлено: фото ВМС США, сделанное помощником фотографа 1-го класса Брайеном Ахо.

Афалина по кличке К-Дог , принадлежащая Программе по изучению морских млекопитающих ВМС США, с установленным на ней датчиком обнаружения, выполняла работы по разминированию в Персидском заливе во время войны в Ираке .

Вооруженные силы США и России тренировали и использовали дельфинов по нескольким причинам. Таких военных дельфинов можно тренировать для спасения потерявшихся водолазов или обнаружения подводных мин . Военные дельфины использовались во время Первой и Второй войны в Персидском заливе .

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Знаете ли вы больше...

...бивень самца нарвала может достигать 3,5 метров в длину, что превышает размер средней самки без рога, и весить до 10 килограммов.

...бивень самца нарвала(ов) — это клык, растущий через губу. Иногда у самца бывает 2 бивня, но их число невелико. У самок нарвала(ов) бивень бывает редко, а если и бывает, то он должен быть меньше, чем у самцов. Также, был зарегистрирован только 1 случай самки нарвала(ов) с двумя рогами

...наблюдения за китообразными восходят, по крайней мере, к классическому периоду в Греции , когда рыбаки делали зазубрины на спинных плавниках дельфинов, запутавшихся в сетях, чтобы спустя годы различать их.

...группы дельфинов-афалин в районе австралийской части Тихого океана продемонстрировали использование базовых инструментов , обматывая клювы кусками губки, чтобы предотвратить ссадины. Это демонстрация когнитивного процесса, похожего на тот, что происходит у человекообразных обезьян .

... Роман Германа Мелвилла «Моби Дик» был вдохновлён реальной жизнью — печально известным самцом кашалота по имени Мокка Дик .

... золотая пластинка «Вояджер» передала в космос песни китов и другие звуки.

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Общие изображения -загрузить новую партию

Ниже приведены изображения из различных статей Википедии, посвященных китообразным.

Image 1Самка гладкого кита с детенышем
Image 2Иллюстрация кита Эдема
Image 3Иллюстрация синего кита
Image 4У археоцетов (как у этого базилозавра ) были гетеродонтные зубы (из Эволюции китообразных )
Image 5Тихоокеанские белобокие дельфины , дельфинирующие (из Зубатый кит )
Image 6Спектрограмма вокализации дельфинов. Свист, визг и щелчки видны как перевернутые буквы V, горизонтальные полосы и вертикальные линии соответственно. (из Toothed whale )
Image 7Виды инфраотряда китообразных (из Эволюции китообразных )
Image 8Их глаза относительно малы для их размера.
Image 9Косатка по имени Улисес выступает в SeaWorld, 2009 г. (из фильма « Зубчатый кит »)
Image 10Останки североатлантического гладкого кита после столкновения с винтом корабля.
Image 11Иллюстрация североатлантического кита
Image 12Дополнительные пластины усиков сужаются в маленькие волоски (от усатого кита ).
Image 13Иллюстрация антарктического полосатика
Image 14Японский научный китобойный промысел пары антарктических малых полосатиков (из Усатого кита )
Image 15Особенности скелета кашалота (из Зубатого кита )
Image 16Скелет Pakicetus attocki (из «Эволюции китообразных »)
Image 17Полосатик Брайда (от усатый кит )
Image 18Скелет горбатого кита. Обратите внимание, как челюсть разделена на две части.
Image 19Скелет гренландского кита с задней конечностью и тазовой костной структурой, обведенной красным. Эта костная структура остается внутренней в течение всей жизни вида. (из Эволюции китообразных )
Image 20График мировой популяции синих китов
Image 21Горбатые киты выпрыгивают из воды во время ловли рыбы с помощью пузырьковой сети
Image 22Возможные связи между китообразными и другими группами копытных. (из Эволюции китообразных )
Image 23Иллюстрация горбатого кита
Image 24Восстановление Janjucetus hunderi (из усатого кита )
Image 25Косатка охотится на тюленя Уэдделла (из Зубатый кит )
Image 26У археомистицетов, как и у яньюцета , были зубы.
Image 27Сердце синего кита и стоящий рядом с ним человек
Image 28Кит, изображенный Конрадом Гесснером в его «Historiae animalium» (1587) (из «Зубчатого кита »).
Image 29Иллюстрация сейвала
Image 30Анатомия дельфина -афалины (из Зубатого кита )
Image 31Протест против научного китобойного промысла Японии
Image 32Оранжевые китовые вши на гладком ките
Image 33Дельфины ( водные млекопитающие ) и ихтиозавры (вымершие морские рептилии ) обладают рядом уникальных приспособлений для полностью водного образа жизни и часто используются в качестве крайних примеров конвергентной эволюции (из Эволюции китообразных )
Image 34Череп акрофизетра (из «Эволюции китообразных »)
Image 35Иллюстрация серого кита
Image 36Атлантического белобокого дельфина, пойманного во время загонной охоты в Хвальбе на Фарерских островах, увозят с помощью вилочного погрузчика (из Зубатый кит )
Image 37Иллюстрация карликового гладкого кита
Image 38Нос кита заполнен восковым веществом, которое широко использовалось в свечах, масляных лампах и смазочных материалах (от Toothed whale ).
Image 39Диаграмма, иллюстрирующая генерацию, распространение и прием звука у зубатого кита. Исходящие звуки обозначены красным, а входящие — зеленым (из Toothed whale )
Image 40Филогенетическое дерево , показывающее взаимоотношения между семействами китообразных. (из книги «Эволюция китообразных »)
Image 41Усатые киты значительно различаются по размеру и форме в зависимости от их поведения при кормлении. (из Усатый кит )
Image 42Иллюстрация обыкновенного малого полосатика
Image 43Мегалодон охотился на миоценовых усатых китов (из Baleen whale )
Image 44Биосонар от китообразных (от зубатого кита )
Image 45Ископаемые останки скуалодона (от зубатого кита )
Image 46Иллюстрация финвала
Image 47Иллюстрация гренландского кита
Image 48Иллюстрация южноатлантического кита