BBC Nature - Whales, dolphins and porpoises videos, news and facts Whales, dolphins and porpoises Whales, dolphins and porpoises Whales, dolphins and porpoises belong to the order Cetacea. These are aquatic mammals that have streamlined bodies highly evolved for swimming. Their hind limbs have become vestigial as part of this streamlining. All whales, dolphins and porpoises are cetaceans, including the biggest animal ever to have lived - the blue whale. Scientific name: Cetacea OERS - Marine Mammal Profiles - Whales, Dolphins, Porpoises, Sea Lions, Seals and Walruses, Manatees and Dugongs, Sea Otters and Polar Bears Marine Mammal Profiles Whales, Dolphins and Porpoises Whales, dolphins and porpoises are fully adapted to aquatic life, exchanging hair and hind limbs for a spindle-shaped body, blowhole, blubber and a tail featuring horizontal flukes. Most species are marine, freshwater dolphins being the exception.

While sharing common characteristics, this group of mammals is one of the most distinct and specialised; it includes the largest mammal (the Blue Whale), well-known dolphins, tusked narwhals and singing humpbacks among others. Whales, dolphins and porpoises can be separated into two general categories depending on whether they employ teeth or instead filter their food from the water using baleen. Species employ a variety of communication and feeding strategies. Whales, dolphins and porpoises all belong to the order Cetacea which is divided into two sub-orders: Mysticeti and Odontoceti. The former are baleen whales which lack teeth as adults, instead using keratin-based baleen plates to strain organisms from the water. Some well-known baleen whales are the blue, humpback and grey whales. Some Mysticetes communicate using complex songs, but they do not use echolocation. The Odontoceti are toothed whales, which employ teeth, that do use echolocation. Dolphins, porpoises and sperm whales all belong to this sub-group. Whales range in size from 33 m (the Blue Whale) to 2.7 m (the Dwarf Sperm Whale).

Whales can be very long-lived and may live more than a century depending on the species. All Mysticetes and some Odontocetes are considered whales. Some whales may stay underwater for lengthy periods of time; the Sperm whale, for example, can stay underwater for up to 2 hours. Dolphins belong to the families Delphinidae and Platanistoidea. They range in size from the over 9 m, 10 tonne Killer whale to the 1.2 m, 40 kg Maui dolphin. Dolphins are found worldwide and are often considered to be among the most intelligent animals. They are social and are often found in pods, communicating through clicks and whistles. Porpoises belong to the family Phocoenidae. They are the smallest cetaceans, the smallest of which is the less then 1.5 m Vaquita. They have flattened, spade-shaped teeth as opposed to the conical teeth of dolphins. Status: Whales, dolphins and porpoises face a variety of threats, many of them strongly influenced by humans. These include climate change, which particularly affects species such as the Bowhead whale that depend on Arctic waters.

While some species are recovering, others are showing decline. According to the IUCN 2006 Red List, of those species evaluated, 2 species are critically endangered, 7 are endangered, 5 are vulnerable, 14 are conservation dependent and 1 is near threatened. In December 2006, the Chinese River Dolphin was declared functionally extinct. Sea Lions, Seals and Walruses While most carnivores live on land, seals, sea lions and walruses have adapted to spending large amounts of time in the water. Unlike whales, dolphins and porpoises, this group spends at least part of its time on land or ice. Sea lions, seals and walruses can be distinguished from one another through a variety of physical and behavioural differences. They live in a variety of habitats ranging from polar to temperate while feeding on food ranging from krill to squid. Sea lions, seals and walruses belong to the sub-order Pinnipedia. Like whales, they utilise a thick layer of blubber both for warmth and for streamlining. Sea lions, also called “eared seals” belong to the family Otariidae and have external ear flaps.

They use their long front flippers to propel them in the water and can bring their hind flippers under their body, allowing them to “walk” on land. They range in size from the 3.3 m Stellar sea lion to the less than 1.3 m Galapagos fur seal. Other seals, also called “true seals” or “earless seals,” belong to the family Phocidae. As the name suggests, they have no external ears. Their hind flippers are shorter than those of Otariids and are used for propulsion in the water while their front flippers are used for locomotion on land. They are more adapted to aquatic life than sea lions and fur seals. They range in size from the 5 m Elephant seal to the less than 1.2 m Baikal seal. The walrus is the sole member of the family Odobenidae. Like Phocids, they lack external ears; like Otariids, they can use their hind flippers to travel on land. In addition to blubber, they also have thick skin (reaching up to 4 cm). Both sexes grow tusks, used for fighting, display, and anchoring themselves to the ice.

Unlike the other pinnipeds, they lack visible fur. The walrus can grow to 4.6 m. Status: Historically, commercial exploitation has driven many seal, sea lion and walrus species to the brink of extinction. Today, many threats such as pollution and entanglement continue to threaten populations. According to the 2006 COSEWIC report, of those species evaluated, 1 species is threatened and 2 species are of special concern within Canada. Manatees and Dugongs Manatees and dugongs are fully aquatic, but, unlike whales and dolphins, they are tolerant to different salinities, but are intolerant to cold and are only found in shallow, tropical waters. Often referred to as sea-cows, manatees and dugongs are the only herbivorous marine mammals. They are large and travel very slowly, and have algae grow on their backs. Manatees belong to the family Trichechidae. They have a large, paddle-shaped tail and have a prehensile upper lip that is used to gather food and also for communication. They can grow up to 3.6 m.

As a manatee wears out its molars, they are replaced by new ones growing in from the back. Only one species of dugong, Dugong dugon, remains. Most dugongs live in the northern waters of Australia. Unlike manatees, they have a fluked tail, incisor tusks and a sharply down-turned snout. They are usually smaller than manatees, but can reach 3 m. Also, they do not replace their teeth as manatees do. Status: Manatees and dugongs are vulnerable to a variety of threats including over-harvesting and habitat destruction. Conflict with humans over coastal habitat threatens populations with greater risk of collisions with boats, pollution, and entanglement. According to the IUCN 2006 Red List, of those species evaluated, 1 species is extinct and 4 species are vulnerable. Sea Otters Sea otters are large otters found in the North Pacific Ocean, spending most of their lives at sea. They have long, streamlined bodies and extremely dense fur. They must consume large amounts of food per day and are often found floating on their backs in kelp forests as they eat and groom. They may either be solitary or congregate in groups.

Otters are part of the family Mustelidae and two species are considered marine mammals: Enhydra lutris (sea otter) and Lutra felina (marine otter). As they do not have a thick layer of blubber, they rely on very dense fur for retaining heat. They also have sebaceous glands that secrete a barrier between water and the skin. They have a special spinal column that allows for great flexibility. They have a high metabolism and consume between 20 and 25% of their body weight each day. The sea otter can reach up to 1.5 m while the marine otter is usually around 1 m. Sea otters are also the only carnivore with less than four lower incisors. Sea otters are found in the North Pacific while the latter are found in southwest South America. Status: Almost hunted to extinction for their fur, pollution, poaching and oil spills all continue to threaten sea otters. According to the IUCN 2006 Red List, the sea otter is endangered. Polar Bears Polar bears are the only marine bear. They are semi-aquatic and spend much of their time on land and ice.

As a result, they lack many of the adaptations to marine life found in other marine mammals. Their range is limited due to their dependence upon the availability of sea ice in order to hunt seals. Although they mostly feed on seals, polar bears will eat anything they can kill. In addition to a thick layer of blubber, polar bears have a dense fur that is hollow and transparent, appearing white to provide camouflage. They also have black skin for absorbing sunlight. Their blubber also acts to aid buoyancy, augmenting the bears’ swimming ability. Polar bears are one of the largest land predators, reaching up to 3.3 m. Status: While polar bears face a variety of threats, including pollution, most attention has been given to the habitat destruction caused by climate change and its drastic effect upon the sea ice. It is estimated that if global warming continues at the present rate, the species will become extinct within 100 years. According to the 2006 COSEWIC report, the polar bear is designated special concern. whale | mammal | Britannica.com mammal Paul Watson Whale, any of the larger species of aquatic mammals belonging to the order Cetacea .

The term whale can be used in reference to any cetacean, including porpoises and dolphins , but in general it is applied to those more than 3 metres (10 feet) long. An exception is the 2.7-metre dwarf sperm whale (Kogia simus), so called for its otherwise striking resemblance to its larger namesake. Whales are the heaviest known animals, living or fossil, reaching a maximum size in the blue whale (Balaenoptera musculus) of perhaps more than 30 metres and 200 metric tons (220 short [U.S.] tons). Whales (order Cetacea). A discussion of whales around the San Juan Islands of Washington, from the documentary … Great Museums Television (A Britannica Publishing Partner) Underwater footage of manta rays, barracudas, sharks, sperm and right whales, seals, and a … Carl Finkbeiner (A Britannica Publishing Partner) Whale watching in Samaná Bay, Dominican Republic. Contunico © ZDF Enterprises GmbH, Mainz Learn about the humpback whale.

Contunico © ZDF Enterprises GmbH, Mainz Whales are distributed throughout the world’s oceans and seas, from the Equator to the polar ice, except for the landlocked Caspian and Aral seas. They are mammals , and they share the defining traits of that group: they breathe air, are warm-blooded, give live birth, suckle their young on milk, and have hair. All are entirely aquatic, with specialized adaptations such as flippers and tail flukes for living in water. Whales must surface regularly to breathe, evacuating their lungs more completely than most mammals in an almost explosive breath known as a blow . Blows are visible because water vapour in the whale’s hot breath condenses when the blow is released. cetacean: Despite living in a medium that has much greater thermal conduction characteristics than air, whales, like other mammals, must regulate their body temperature. Hair, however, is restricted to the head, appearing mainly as isolated whiskers (vibrissae) near the mouth and blowhole. Blubber serves as an insulating layer to protect small whales from hypothermia .

Large whales have the opposite problem in that they can produce too much heat; they possess elaborate thermoregulation mechanisms to prevent overheating. Similar Topics sea otter Because of the restricted utility of vision underwater, whales use sound to perceive and interpret their environment and to communicate, sometimes over vast distances. Biologists have computed that the 10-hertz sounds of fin whales (Balaenoptera physalus), for example, can travel over 1,800 km (1,100 miles). Toothed whales can produce sounds and interpret their reflections via active echolocation . The extent to which baleen whales have this ability is unknown. Following internal fertilization, female whales are pregnant for about a year. The young are relatively large when born—one-third to one-half the length of the mother. They are nursed for about six months on extremely rich milk containing almost 50 percent fat. Whales have one pair of nipples located at the rear of the abdomen near the genital opening. The first fossil whales are known from rocks approximately 50 million years old (Early Eocene Epoch ). These members of the extinct suborder Archaeoceti are the primitive whales from which modern whales are derived.

They show many similarities to terrestrial mammals, including a differentiated dentition (heterodonty) consisting of incisors, canines, premolars, and molars. Archaeocetes gave rise to the living suborders: the baleen whales (suborder Mysticeti) and the toothed whales (suborder Odontoceti). Mysticetes have baleen plates and take small prey by the mouthful, mainly in the form of drifting (planktonic) crustaceans such as copepods and krill , but they also occasionally consume small schooling fish or squid . One interesting departure from this pattern is the gray whale (Eschrichtius robustus), which commonly eats shrimp and other bottom-dwelling creatures: it scoops up mud and strains it through the baleen plates, retaining its food. Odontocetes have simple teeth (homodonty) and pursue individual squid, fish, and other prey. The largest odontocete, the sperm whale (Physeter catodon), occasionally feeds on giant squid. Britannica Stories whale - Student Encyclopedia (Ages 11 and up) It weighs as much as 20 elephants but lives beneath the sea.

The blue whale is Earth’s largest animal. Larger than the largest of ancient dinosaurs, blue whales can grow to be more than 100 feet (30 meters) long and weigh nearly 150 tons. Not all whales are so large. The much smaller pilot whale grows to about 28 feet (8.5 meters) in length, and dolphins, which belong to the whale family, range only from 3 to 13 feet (1 to 4 meters). Although whales spend their lives in the sea, they are, like humans, endothermic, or warm-blooded, mammals. After a baby whale is born, it nurses on its mother’s milk, just like the young of land mammals. Article Contributors Marine Mammals :: NOAA Fisheries Marine Mammals Photo: NMFS Pacific Islands Fisheries Science Center North Atlantic Right whales Photo: NMFS Southwest Fisheries Science Center Humpback whale Photo: Janice Waite, National Marine Mammal Laboratory Northern fur seal Photo: NOAA's National Marine Mammal Laboratory Bottlenose dolphin Photo: NMFS Southwest Fisheries Science Center Beluga whale Photo: NOAA's National Marine Mammal Laboratory Credit: Alaska Fisheries Science Center, NOAA Ocean Media Center Dr.

Brian Stacy, NOAA veterinarian, cleans a young Kemp's ridley turtle Photo: NOAA/FWCC Sea Turtles, Dolphins, and Whales and the Gulf of Mexico Oil Spill Marine mammals are mammals that are well adapted for life in the marine environment. Two major groups of marine mammals are: Cetaceans: There are approximately 217 marine mammal species worldwide managed under the MMPA. All marine mammals are protected under the Marine Mammal Protection Act (MMPA) ; some marine mammals may be designated as "depleted" under the MMPA. Endangered and threatened marine mammals are also protected under the Endangered Species Act (ESA) . Stocks of marine mammals may also be considered "strategic" under the MMPA. A list of strategic/ non-strategic stocks [pdf] can be found in the summary tables of the Stock Assessment Reports . The following list of marine mammals includes those under our jurisdiction, which includes marine mammal species found in U.S. waters, as well as endangered/ threatened species worldwide. (The U.S.

Fish and Wildlife Service manages walrus , polar bear , otter , manatee , and dugong .) Dolphins The Marine Mammal Center : Cetaceans Sea Otter Cetaceans: Whales, Dolphins, and Porpoises Marine mammals in the cetacean family include whales, dolphins, and porpoises. Although whales spend all their time in the oceans, they are mammals just like us. This means that they are warm blooded, give birth to live young, nurse their young, have traces of hair or fur, and must come to the surface to breathe air through their lungs. Millions of years ago, the ancestors of whales lived on land. Scientists believe these land ancestors looked like small dogs, but were probably more closely related to hippos and went into the ocean about 60 million years ago. Over time, these ancestors adapted to survive solely in the ocean environment. Their front legs turned into paddle-shaped flippers, they lost their back legs, their tails grew larger and widened to form flukes, and they developed a thick layer of fat, called blubber, to keep warm in the ocean.

Also, their skulls elongated and the nostrils shifted to the top of their heads (blowholes) to aid in breathing at the ocean's surface. They developed a series of adaptations related to diving, which include the ability to store more oxygen in their blood and muscles and having more blood volume relative to their body size than land mammals. Classification Cetaceans are separated into two groups: toothed and baleen whales. As their name suggests, toothed whales (or odontocetes) have teeth. They also have one opening at their blowhole. There are over 73 species of toothed whales, including sperm and beaked whales, belugas and narwhals, porpoises and dolphins, and even fresh water dolphins that live in rivers. They range in size from the 60-foot (21.1 m) sperm whale to the 5-foot (1.5 m) vaquita. Some toothed whales are quite unusual. For instance, the beaked whales spend most of their time in the deep water and, therefore, are rarely encountered by people, and new species are still being discovered! Some beaked whales are odd looking and often only the males will have teeth.

The straptoothed whales have only two teeth, which wrap around the top of their jaws so they cannot fully open their mouths! Toothed whales tend to be social and live in groups. Like bats, they use echolocation or sonar to detect objects in their environment. They produce sounds in the air passages in their heads, which are then projected out in front of them. The sound bounces off solid objects and returns to them (like an echo), so the animals are able to get a "picture" of what is around them. A lot of research is being done on whale sounds. Many species, such as the humpback and sperm whales, seem to have individually identifiable calls. Orcas (killer whales) live in groups or pods and each pod has a dialect or accent, just like we have accents depending upon which part of the world we are from. The baleen whales (or mysticetes) are the other group of cetaceans. This group includes 11 species ranging in length from the pygmy right whale at 21 feet (6.4 m) to the largest whale, the blue whale at 100 feet (30.5 m).

Baleen whales have two blowholes and instead of teeth, have hundreds of rows of baleen plates, which are made of keratin, a substance in our hair and fingernails. The baleen strains out small fish and plankton from the water for food. Most baleen whales feed by taking a large mouthful of food and water, and then push the water out gaps between their baleen plates with their tongues. The food gets trapped on the inside fringed edge of the baleen. Most baleen whales eat krill (shrimp-like animals) or small fish. Right and bowhead whales are baleen whales that feed in a slightly different way called skimming. Water and food flows through a gap in the front of their mouth where the baleen is missing and the food gets trapped in the baleen fringe while the water flows out between the baleen plates. Even though baleen whales eat very small animals, which are low on the food chain, these whales are all very large and eat great quantities at once. For instance, the blue whale is the largest animal on earth, weighing up to 150 tons.

Baby blue whales gain 10 pounds (4.5 kg) an hour! Current Status Many whales are endangered, largely due to past hunting. Years ago, people used the oil from the blubber of whales for all sorts of items, including oil burned in lamps and ingredients for manufacturing lipstick. They also used whale meat to eat or make pet food, sinews for tennis racquet strings, and even used baleen as stays or supports in ladies underwear. A waxy substance called ambergris, which is from a sperm whale's digestive system, was used in making perfume. Ambergris was very valuable and a large lump found by a beachgoer was worth a fortune. Since 1986, there has been a ban or moratorium on hunting the large whales for commercial uses. However, some countries still kill whales for scientific purposes, and others have illegally resumed commercial whaling. This is controversial because the products from these whales are still used commercially. Many scientists question whether the whales really need to be killed to learn the sorts of things being studied. Certain Native American tribes are still allowed to hunt whales for subsistence. These hunts are regulated with specific rules for the method of hunting and yearly quotas that limit the number of whales taken.

Many people are concerned about the fate of the small whales (the dolphins and porpoises). Thousands die every year from getting caught in fishing nets and plastic trash. Toxins and pollution in the ocean are affecting the health of these animals and likely their ability to fight off diseases. Around the world, there has been an increase in reported strandings of marine mammals. Other species are suffering due to loss of their habitat. Sometimes even whale watching can interfere with and harass whales, if the boats venture too close to the whales or separate mothers from calves. Small whales are sometimes captured for display in aquaria and even hotels, and many people question the quality of life and health for these animals. Other species of small whales are still sometimes hunted and eaten in some parts of the world. In the recent past, popular movements helped to save the whales from hunting. Unfortunately, the whales are not completely safe. We need to understand and solve some of the problems currently threatening whales like climate change, boat strikes, entanglement in nets, and noise pollution. You can help by learning about the issues, letting others know what you have learned, and writing to lawmakers. Also, if you ever have the chance, try to see live whales in the wild.

You will never forget it! Whale Alert Among the many threats faced by whales today are ship strikes, which occur more and more in busy shipping lanes. A collaboration of government agencies, academic institutions, non-profit conservation groups and private sector companies have developed Whale Alert, an app that helps reduce the chance of fatal ship strikes by large vessels. The app can be used by anyone out on the water to report concentrations of cetaceans. It displays active whale management areas, required reporting areas, recommended routes, areas to be avoided and near real-time warnings in shipping lanes along the east and west coasts of the United States and Canada. This information allows vessel operators to avoid collision with whales by slowing down and heightening their visual awareness. Visit these websites to download the Whale Alert app and learn more: Cetacean Facts & Information - WDC Tim Stenton Variety ‘Cetaceans’ is the collective name for all whales, dolphins and porpoises who between them form a single group, known as an order. It's a huge group, though, comprising around 90 species, so let's break it down. To begin with, cetaceans can be divided into two categories; baleen whales, and toothed whales.

Baleen plates, or whalebone, are comb-like bristles that hang from the upper jaw of most large whales and allow them to filter-feed. When whales open their mouths, water and prey, such as krill or small fish upon which they feed, pour in. The water floods back out but the baleen filters out the prey for the whale to then swallow. Blue , humpback , gray and right whales are all included in this group. The vast majority of whales and dolphins, however, belong in the toothed category, and they feed on prey in a similar manner to most carnivores. These include the beaked whales, the dolphins and the porpoises. The sperm whale also sits here (the only large whale in this category) as do the beluga and narwhal . The dolphins form the largest group, and (rather confusingly) include the orca , or killer whale, as well as the pilot whales . Marine dolphins can be found all around the world, varying in size and colouration, but rarely coming closer inland than bays or estuaries. There are a few species of freshwater dolphins , however, which are found in some of the largest of the world's rivers.

Sadly, one of them, the Yangtze River dolphin , was declared functionally extinct in 2007. Beaked whales are the least known of all cetaceans, as they principally lead their lives in deep waters. There are at least 20 different species in all. The porpoises are distinguished from dolphins by their stubbier beaks and flatter teeth. With such a wide range of skills, feeding habits, behavioural patterns and more, there's a whale, dolphin or porpoise to suit virtually every aquatic environment on the planet. Society To give the well-known phrase a twist, no whale or dolphin is an island. These marine mammals are in fact highly social, sometimes forming superpods of 1,000 individuals or more. These wide-ranging communities, or societies, are not just for company either. They are built upon complex structures and levels of interdependence that can only be forged from the strongest of social bonds. In some dolphin societies, for example, groups will stay with injured or sick individuals, even physically supporting them to the surface if necessary so that they can breathe. Roles are very important in whale and dolphin societies.

Older individuals often act as surrogate parents or as guardians of crèches, so that responsibilities can be shared around a group. Feeding systems, migratory patterns, group play and much more are all based on these strong social systems. Communication is vital in all these circumstances, and whales and dolphins have developed some of the richest languages known. Clicks, grunts, whistles, calls, songs and more of extraordinary variety provide them with extensive vocabularies that cover all situations. Scientists are still trying to unravel the complexities of these languages, and it will be a long time before we are even close to understanding the full range. One thing is certain: it is only within the heart of their communities that whales and dolphins can lead their lives to the full. Back to the water There are many mammals that spend time in the water. Seals, sea lions, walruses, water voles, the platypus and many more are capable of prolonged periods swimming above or below the surface, but all of them come onto the land. What makes whales, dolphins and porpoises different to all of these is that they live entirely in the water. Unsurprisingly, therefore, scientists were rather baffled for centuries.

Why on earth would a mammal, which needs to breathe air, and which has a bone structure, including vestigial limbs, that would suggest land-based movement, have evolved in an entirely aquatic environment? 'Why on earth' was the question that eventually became its own answer. Originally, it was thought they were related to an extinct group of carnivorous hoofed mammals, which had teeth similar to those of whales. In recent decades, however, a remarkable animal called the Pakicetus has been discovered, which had similarly positioned and shaped ear bones to modern whales, as well as similarly arranged teeth. Many of the 40-50 million year old fossils of Pakicetus have been found near water bodies, and it is now thought that they were aquatic mammals, forerunners to the whales and dolphins themselves. The fact that the modern descendants are carnivorous suggests that they found an unchallenged niche in the water, and stayed there, steadily evolving until they no longer needed their land-based abilities. In fact, it's believed by many that the closest living relative to whales and dolphins is another mammal that spends much of its time in the water - the hippopotamus.

Behaviour If you've ever watched whales or dolphins out at sea, or even just seen photographs of them, you'll know that there's often much more to look at than just a fin poking out of the water. Heads, tails, sometimes entire bodies are thrust above the surface, in a glorious mixture of behaviours, each of which signifies something special. Perhaps you've seen dolphins swimming along the pressure wave caused by a boat: this is known as bow-riding, which must be great fun for them. At quieter times they might be seen 'logging', the term given to floating on the water's surface, a great energy saving position. Then there's lobtailing, sometimes known as tail-slapping, which is just what it describes: a hard smack of the water by a whale's fluke, or tail. One of the reasons this might be done is in order to cause a loud sound to stun or confuse prey. When the other end of the body appears - i.e. the head - for a good look around, then this is known as spyhopping. The most exciting sight to see above the waves, however, and the one that most people love to catch on camera if possible, is breaching.

Humpback whales are particularly fond of leaping clear of the water in this way, and there are a number of theories as to why they do it. It could be to dislodge parasites, it could be to create a similar effect to lobtailing, it could be an element of communication within social groups... or it could, quite simply, be the sheer pleasure of exuberant play. Did you know? The narwhal's tusk is in fact a canine tooth that can grow up to 3m in length. It is thought to be a symbol of sexual power within males, rather like a lion's mane, helping to establish rank within hierarchies. Sperm whales can reach depths of around 3km beneath the ocean's surface, staying submerged for up to two hours. What are they doing down there? One of their favourite foods is giant squid, which lives in the depths of the ocean. Occasionally sperm whales are seen with scars obtained from their deep sea battles. There's a species of toothed whale called the Perrin's beaked whale , and rather remarkably, no-one has ever knowingly seen a live one.

In the 1970s, a few dead individuals were discovered on the Californian coastline, and were identified as other species. Later DNA testing of them revealed that they were in fact a completely new species to science, and they were given the name Perrin's beaked whale. No-one has positively identified one since. All toothed whales, including dolphins and porpoises, have a melon. This sounds rather an odd statement, until you realise that 'melon' is the term given to a fatty organ in their forehead which is thought to be used to aid echolocation. In some species, such as the beluga, the melon can cause a pronounced cranial bulge. Belugas , the all-white toothed whales of the Arctic, are often known as sea canaries because of their high-pitched twitter. The large whales known as rorquals all have pronounced grooves that run from their mouths and along the underside of their bodies. These grooves, which are actually folds of skin, enable the mouth to widen in huge gapes when feeding. The word 'rorqual' itself actually comes from the Norwegian for 'furrow whale'.

Related news and blogs Whale, Dolphin, and Porpoise Order | Britannica.com Whale, Dolphin, and Porpoise Order Cetacea any member of an entirely aquatic group of mammals commonly known as whales, dolphins, and porpoises. Displaying Featured Whale, Dolphin, and Porpoise Order Articles sperm whale Physeter catodon the largest of the toothed whales, easily recognized by its enormous square head and narrow lower jaw. The sperm whale is dark blue-gray or brownish, with white patches on the belly. It is thickset and has small paddlelike flippers and a series of rounded humps on its back. Males attain a maximum length of about 19 metres (62 feet)... blue whale Balaenoptera musculus the most massive animal ever to have lived, a species of baleen whale that weighs approximately 150 tons and may attain a length of more than 30 metres (98 feet). The largest accurately measured blue whale was a 29.5-metre female that weighed 180 metric tons (nearly 200 short [U.S.] tons), but there are reports of 33-metre catches...

killer whale Orcinus orca largest member of the dolphin family (Delphinidae). The killer whale is easy to identify by its size and striking coloration: jet black on top and pure white below with a white patch behind each eye, another extending up each flank, and a variable “saddle patch” just behind the dorsal fin. Despite the fact that this cetacean is a powerful... dolphin any of the toothed whales belonging to the families Delphinidae (oceanic dolphins) or Platanistidae (river dolphins). Of the approximately 40 species of dolphins in the Delphinidae, 6 are commonly called whales, including the killer whale and the pilot whales. Most dolphins are small, measuring less than 3 metres (10 feet) in length, and have spindle-shaped... narwhal Monodon monoceros a small, toothed whale found along coasts and in rivers throughout the Arctic. Males possess a long, straight tusk that projects forward from above the mouth. Narwhals lack a dorsal fin, and in adults the flippers are turned upward at the tips. Their mottled gray bodies are darker above than below, and they usually attain a length...

whale any of the larger species of aquatic mammals belonging to the order Cetacea. The term whale can be used in reference to any cetacean, including porpoises and dolphins, but in general it is applied to those more than 3 metres (10 feet) long. An exception is the 2.7-metre dwarf sperm whale (Kogia simus), so called for its otherwise striking resemblance... humpback whale Megaptera novaeangliae a baleen whale known for its elaborate courtship songs and displays. Humpbacks usually range from 12 to 16 metres (39 to 52 feet) in length and weigh approximately 36 metric tons (40 short [U.S.] tons). The body is black on the upper surface, with a variable amount of white below, and it has about 30 broad ventral grooves on... beluga Delphinapterus leucas a small, toothed whale found mainly in the coastal waters of the Arctic Ocean and adjacent seas but also in rivers and deep offshore waters.

It is an extremely vocal cetacean and thus has also been referred to as the “canary of the sea.” This whale can also proficiently mimic a variety of sounds. Easily caught in shallow water,... cetacean Cetacea any member of an entirely aquatic group of mammals commonly known as whales, dolphins, and porpoises. The ancient Greeks recognized that cetaceans breathe air, give birth to live young, produce milk, and have hair —all features of mammals. Because of their body form, however, cetaceans were commonly grouped with the fishes. Cetaceans are entirely... porpoise Phocoenidae specifically, any of seven species of toothed whales distinguishable from dolphins by their more compact build, generally smaller size (maximum length about 2 metres, or 6.6 feet), and curved, blunt snouts with spatulate rather than conical teeth. In North America the name is sometimes applied to dolphins. The porpoise family consists of... baleen whale Mysticeti any cetacean possessing unique epidermal modifications of the mouth called baleen, which is used to filter food from water. Baleen whales seek out concentrations of small planktonic animals.

The whales then open their mouth and take in enormous quantities of water. When the mouth is closed, they squeeze the water out through the sides, catching... fin whale Balaenoptera physalus a slender baleen whale, second in size to the blue whale and distinguishable by its asymmetrical coloration. The fin whale is generally gray with a white underside, but the right side of the head has a light gray area, a white lower jaw, and white baleen at the front of the mouth. The fin whale is 18–27 metres (59–89 feet) long,... gray whale Eschrichtius robustus a slender baleen whale having a profusion of external parasites that give it the appearance of a barnacle -encrusted rock. The gray whale attains a maximum length of about 15 metres (49 feet). It is gray or black, mottled with white, and has short yellow baleen with coarse bristles. There are two (rarely more) lengthwise grooves... right whale Balaenidae any of four species of stout-bodied whales having an enormous head measuring one-quarter to one-third their total body length.

From the 17th to 19th century, these whales were hunted for their oil and their strong, elastic baleen. Because of the considerable economic value of these products, this cetacean gained its name because it was the... pilot whale Globicephala either of two species of small, slender toothed whales with a round, bulging forehead, a short beaklike snout, and slender, pointed flippers. Pilot whales are about 4–6 metres (13–20 feet) long and are found in all the oceans of the world except the Arctic. Males are larger than females, but both are black and some have a pale, elongated,... sei whale Balaenoptera borealis species of baleen whale capable of short bursts of speed that make it the swiftest of the rorquals. Usually attaining a length of about 13–15 metres (43–49 feet), this cetacean is bluish gray or blackish above with paler underparts and a relatively large hook-shaped (falcate) dorsal fin. The throat and chest have about 50 short...

toothed whale Odontoceti any of the odontocete cetaceans, including the oceanic dolphins, river dolphins, porpoises, pilot whales, beaked whales, and bottlenose whales, as well as the killer whale, sperm whale, narwhal, and beluga whale. The ancestors of present-day odontocetes probably evolved during the Oligocene Epoch (33.7 million to 23.8 million years ago)... Basilosaurus extinct genus of primitive whales of the family Basilosauridae (suborder Archaeoceti) found in Middle and Late Eocene rocks in North America and northern Africa (the Eocene Epoch lasted from 55.8 million to 33.9 million years ago). Basilosaurus had primitive dentition and skull architecture; the rest of the slender, elongated skeleton was well adapted... rorqual Balaenoptera any of five particular species of baleen whales —specifically the blue whale, fin whale, sei whale, Bryde’s whale, and minke whale.

The term is often extended to include the humpback whale (Megaptera novaeangeliae), the only other member of the family Balaenopteridae, in which case rorqual becomes synonymous with the family name. Rorquals... river dolphin any of six species of small, usually freshwater aquatic mammals that are related to whales (order Cetacea). These dolphins are found in rivers of south-central Asia, China, and South America and in the coastal waters of Brazil, Argentina, and Uruguay. River dolphins have long beaks and rounded foreheads, distinguishing them from more familiar-looking... beaked whale Ziphiidae any of 22 species of medium-sized toothed whales with extended snouts, including the bottlenose whales. Little is known about this family of cetaceans; one species was first described in 1995, two others are known only from skeletal remains, and the bodies of undescribed species occasionally drift ashore. Natural history In addition to the... Pakicetus extinct genus of early cetacean mammals known from fossils discovered in 48.5-million-year-old river delta deposits in present-day Pakistan.

Pakicetus is one of the earliest whales and the first cetacean discovered with functional legs. In addition, it still retained many other features of terrestrial mammals, including an auditory system that was... grampus Grampus griseus a common offshore inhabitant of tropical and temperate ocean waters, a member of the dolphin family (Delphinidae). The grampus measures about 4 metres (approximately 13 feet) in length and has a blunt head and a distinct longitudinal forehead crease. It is unique among dolphins in usually having no upper teeth and from zero to seven... Roy Chapman Andrews naturalist, explorer, and author, who led many important scientific expeditions for which he obtained financial support through his public lectures and books, particularly on central Asia and eastern Asia. After graduating from Beloit (Wis.) College in 1906, he took a position at the American Museum of Natural History in New York City. In 1908 he went... bottlenose whale any of four species of beaked whales distinguished by a bulbous forehead that drops sharply to the base of the beak. All inhabit deep offshore waters and eat squid, fish, and various bottom-dwelling animals.

Bottlenose whales are capable of long, deep dives; biologists recorded the dive of one northern bottlenose (Hyperoodon ampullatus) to almost 1,500... basilosaurid any member of the family Basilosauridae, an early group of whales that lived from the middle Eocene to the late Oligocene Epoch (about 41 million to 23 million years ago). Basilosaurids occurred worldwide during most of their history, and important fossils have been recovered in Egypt and the southern United States. Their diversity was highest during... Simocetus dolphinlike toothed whale (or odontocete) from the late Oligocene (28 million to 23 million years ago) known for its unusual facial characteristics. The fossil remains of Simocetus were found in the Alsea Formation, a geologic marine sequence made up of fine muds and sands on Oregon ’s Pacific coast near the mouth of the Yaquina River. Despite its... bottlenose dolphin Tursiops any of three species of oceanic dolphins classified within the marine mammal family Delphinidae and characterized by a bottle-shaped snout.

The common bottlenose dolphin (Tursiops truncatus), which is the most widely recognized dolphin species, is found worldwide in warm and temperate seas. In contrast, the Indian Ocean bottlenose dolphin... Llanocetus denticrenatus earliest known baleen whale and sole member of the family Llanocetidae, suborder Mysticeti. Llanocetus denticrenatus lived during the Late Eocene (33.9 million to 38 million years ago). Much of what is known about the species comes from an analysis of an endocast (a cast of the brain cavity) and part of a jaw from a fossil excavated in 1974 and 1975... list of cetaceans Cetaceans (order Cetacea) are an entirely aquatic order of mammals comprising the whales, the dolphins, and the porpoises. The ancient Greeks recognized that cetaceans breathe air, give birth to live young, produce milk, and have hair—all features of mammals. Because of their body form, however, cetaceans were once commonly (and incorrectly) grouped...

The evolution of whales The evolution of whales print The evolution of whales The first thing to notice on this evogram is that hippos are the closest living relatives of whales, but they are not the ancestors of whales. In fact, none of the individual animals on the evogram is the direct ancestor of any other, as far as we know. That's why each of them gets its own branch on the family tree. Hippos are large and aquatic, like whales, but the two groups evolved those features separately from each other. We know this because the ancient relatives of hippos called anthracotheres (not shown here) were not large or aquatic. Nor were the ancient relatives of whales that you see pictured on this tree  such as Pakicetus. Hippos likely evolved from a group of anthracotheres about 15 million years ago, the first whales evolved over 50 million years ago, and the ancestor of both these groups was terrestrial. These first whales, such as Pakicetus, were typical land animals. They had long skulls and large carnivorous teeth. From the outside, they don't look much like whales at all.

However, their skulls  particularly in the ear region, which is surrounded by a bony wall  strongly resemble those of living whales and are unlike those of any other mammal. Often, seemingly minor features provide critical evidence to link animals that are highly specialized for their lifestyles (such as whales) with their less extreme-looking relatives. Skeletons of two early whales. Compared to other early whales, like Indohyus and Pakicetus, Ambulocetus looks like it lived a more aquatic lifestyle. Its legs are shorter, and its hands and feet are enlarged like paddles. Its tail is longer and more muscular, too. The hypothesis that Ambulocetus lived an aquatic life is also supported by evidence from stratigraphy  Ambulocetus's fossils were recovered from sediments that probably comprised an ancient estuary  and from the isotopes of oxygen in its bones. Animals are what they eat and drink, and saltwater and freshwater have different ratios of oxygen isotopes. This means that we can learn about what sort of water an animal drank by studying the isotopes that were incorporated into its bones and teeth as it grew.

The isotopes show that Ambulocetus likely drank both saltwater and freshwater, which fits perfectly with the idea that these animals lived in estuaries or bays between freshwater and the open ocean. Isotopic analyses help us figure out the likely habitats of extinct whales like Ambulocetus. Whales that evolved after Ambulocetus (Kutchicetus, etc.) show even higher levels of saltwater oxygen isotopes, indicating that they lived in nearshore marine habitats and were able to drink saltwater as today's whales can. These animals evolved nostrils positioned further and further back along the snout. This trend has continued into living whales, which have a "blowhole" (nostrils) located on top of the head above the eyes. As whales evolved increasingly aquatic lifestyles, they also evolved nostrils located further and further back on their skulls. These more aquatic whales showed other changes that also suggest they are closely related to today's whales. For example, the pelvis had evolved to be much reduced in size and separate from the backbone. This may reflect the increased use of the whole vertebral column, including the back and tail, in locomotion.

If you watch films of dolphins and other whales swimming, you'll notice that their tailfins aren't vertical like those of fishes, but horizontal. To swim, they move their tails up and down, rather than back and forth as fishes do. This is because whales evolved from walking land mammals whose backbones did not naturally bend side to side, but up and down. You can easily see this if you watch a dog running. Its vertebral column undulates up and down in waves as it moves forward. Whales do the same thing as they swim, showing their ancient terrestrial heritage. As whales began to swim by undulating the whole body, other changes in the skeleton allowed their limbs to be used more for steering than for paddling. Because the sequence of these whales' tail vertebrae matches those of living dolphins and whales, it suggests that early whales, like Dorudon and Basilosaurus, did have tailfins. Such skeletal changes that accommodate an aquatic lifestyle are especially pronounced in basilosaurids, such as Dorudon. These ancient whales evolved over 40 million years ago.

Their elbow joints were able to lock, allowing the forelimb to serve as a better control surface and resist the oncoming flow of water as the animal propelled itself forward. The hindlimbs of these animals were almost nonexistent. They were so tiny that many scientists think they served no effective function and may have even been internal to the body wall. Occasionally, we discover a living whale with the vestiges of tiny hindlimbs inside its body wall. Skeleton of the early whale Dorudon. Notice the tiny hind limbs at left below the tail. This vestigial hindlimb is evidence of basilosaurids' terrestrial heritage. The picture below on the left shows the central ankle bones (called astragali) of three artiodactyls, and you can see they have double pulley joints and hooked processes pointing up toward the leg-bones. Below on the right is a photo of the hind foot of a basilosaurid. You can see that it has a complete ankle and several toe bones, even though it can't walk. The basilosaurid astragalus still has a pulley and a hooked knob pointing up towards the leg bones as in artiodactyls, while other bones in the ankle and foot are fused.

From the ear bones to the ankle bones, whales belong with the hippos and other artiodactyls. At left, the ankle bones of two middle Eocene protocetid archaeocetes, Rodhocetus balochistanensis (left) and Artiocetus clavis (right) from Pakistan, compared to those of the pronghorn Antilocapra americana (center). At right, the ankle region and foot of Basilosaurus. The pulley part of the astragalus (outlined) connects to the tibia and fibula. Whale phylogeny from The Tangled Bank, used with permission of the author, Carl Zimmer, and publisher, Roberts & Company, Greenwood Village, Colorado; Photos of Dorudon, extinct whale and pronghorn ankle bones, and Basilosaurus foot © 1998, 1991 and 2001, respectively, Philip Gingerich. Photo of Pakicetus and Ambulocetus courtesy of J.G.M. Thewissen, from: J.G.M. Thewissen, L.N. Cooper, J.C. George, and S. Bajpai. 2009.

From land to water: The origin of whales, dolphins, and porpoises. Evolution: Education & Outreach 2:272-288. Isotopic analyses data from: Bajpai, S., and P.D. Gingerich. 1998. A new Eocene archaeocete (Mammalia, Cetacea) from India and the time of origin of whales. Proceedings of the National Academy of Sciences 95:15464-15468. Barrick, R.E., A.G. Fischer, Y. Kolodny, B. Luz, and D. Bohaska. 1992. Cetacean bone oxygen isotopes as proxies for Miocene ocean compostion and glaciation. Palaios 7(5):521-531. Thewissen, J.G.M., L.J. Roe, J.R. O'Neil, S.T. Hussain, A. Sahni, and S. Bajpai. 1996. Evolution of cetacean osmoregulation. Nature 381:379-380.

Yoshida, N., and N. Miyazaki. 1991. Oxygen isotope correlation of cetacean bone phosphate with environmental water. Journal of Geophysical Research 96(C1):815-820. Evogram examples Wow! How big the whale - YouTube Wow! How big the whale Want to watch this again later? Sign in to add this video to a playlist. Need to report the video? Sign in to report inappropriate content. Rating is available when the video has been rented. This feature is not available right now. Please try again later. Published on Aug 1, 2016 Whale is the common name for a widely distributed and diverse group of fully aquatic placental marine mammals. They are an informal grouping within the infraorder Cetacea, usually excluding dolphins and porpoises. Whales, dolphins and porpoises belong to the order Cetartiodactyla with even-toed ungulates and their closest living relatives are the hippopotamuses, having diverged about 40 million years ago.

The two parvorders of whales, baleen whales (Mysticeti) and toothed whales (Odontoceti), are thought to have split apart around 34 million years ago. The whales comprise eight extant families: Balaenopteridae (the rorquals), Balaenidae (right whales), Cetotheriidae (the pygmy right whale), Eschrichtiidae (the gray whale), Monodontidae (belugas and narwhals), Physeteridae (the sperm whale), Kogiidae (the dwarf and pygmy sperm whale), and Ziphiidae (the beaked whales). Whales are creatures of the open ocean; they feed, mate, give birth, suckle and raise their young at sea. So extreme is their adaptation to life underwater that they are unable to survive on land.

Whales range in size from the 2.6 metres (8.5 ft) and 135 kilograms (298 lb) dwarf sperm whale to the 34 metres (112 ft) and 190 metric tons (210 short tons) blue whale, which is the largest creature that has ever lived. The sperm whale is the largest toothed predator on earth. Several species exhibit sexual dimorphism, in that the females are larger than males. Baleen whales have no teeth; instead they have plates of baleen, a fringe-like structure used to expel water while retaining the krill and plankton which they feed on. They use their throat pleats to expand the mouth to take in huge gulps of water. Balaenids have heads that can make up 40% of their body mass to take in water. Toothed whales, on the other hand, have conical teeth designed for catching fish or squid. Baleen whales have a well developed sense of "smell", whereas toothed whales have well-developed hearing − their hearing, that is adapted for both air and water, is so well developed that some can survive even if they are blind.

Some species, such as sperm whales, are well adapted for diving to great depths to catch squid and other favoured prey. Whales have evolved from land-living mammals. As such they must breathe air regularly, though they can remain submerged for long periods. They have blowholes (modified nostrils) located on top of their heads, through which air is taken in and expelled in the form of vapour. They are warm-blooded, and have a layer of fat, or blubber, under the skin. With streamlined fusiform bodies and two limbs that are modified into flippers, whales can travel at up to 20 knots, though they are not as flexible or agile as seals. Whales produce a great variety of vocalizations, notably the extended songs of the humpback whale. Although whales are widespread, most species prefer the colder waters of the Northern and Southern Hemispheres, and migrate to the equator to give birth. Species such as humpbacks and blue whales are capable of travelling thousands of miles without feeding. Males typically mate with multiple females every year, but females only mate every two to three years. Calves are typically born in the spring and summer months and females bear all the responsibility for raising them.

Mothers of some species fast and nurse their young for a relatively long period of time. Once relentlessly hunted for their products, whales are now protected by international law. The North Atlantic right whales nearly became extinct in the twentieth century, with a population low of 450, and the North Pacific gray whale population is ranked Critically Endangered by the IUCN. Besides whaling, they also face threats from bycatch and marine pollution. The meat, blubber and baleen of whales have traditionally been used by indigenous peoples of the Arctic. Whales have been depicted in various cultures worldwide, notably by the Inuit and the coastal peoples of Vietnam and Ghana, who sometimes hold whale funerals. Whales occasionally feature in literature and film, as in the great white whale of Herman Melville's Moby Dick. Small whales, such as belugas, are sometimes kept in captivity and trained to perform tricks, but breeding success has been poor and the animals often die within a few months of capture. Whale watching has become a form of tourism around the world. -~-~~-~~~-~~-~-

Question: Whales, porpoises and dolphins belong to which group of aquatic mammals?
Answer: CETACEANS