Whales

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Whales
Humpback whale (Megaptera novaeangliae)

Humpback whale ( Megaptera novaeangliae )

Systematics
Class : Mammals (mammalia)
Subclass : Higher mammals (Eutheria)
Superordinate : Laurasiatheria
without rank: Scrotifera
without rank: Cetartiodactyla
Order : Whales
Scientific name
Cetacea
Brisson , 1762
Submissions

The whales (Cetacea) form an order of mammals with around 90  species that live exclusively in water. There are two submissions: the baleen whales (Mysticeti) posing as filter feeders of plankton feed, for which the largest animals on evolutionary history are, as well as the predatory living toothed whales (Odontoceti), including the family of dolphins (Delphinidae) belongs. The term “whale” can in a linguistically narrower sense exclude the species designated as “dolphins” (which are not entirely congruent with the family), so that the whole order is also referred to as “whales and dolphins”.

The old popular name “whale”, which initially dominates in New High German and is now popular, does not correspond to today's scientific understanding, since whales are not fish , but aquatic (water-living) mammals ( marine mammals ). In antiquity and up to the middle of modern times, however, going back to Aristotle , they were regarded as fish, although the philosopher of the fourth century BC had already recognized various physiological similarities with the terrestrial vertebrates . It was not until Carl von Linné that whales were assigned to mammals in 1758.

With the exception of individual dolphins and the various groups of river dolphins, whales live in the ocean . This group of mammals made the transition to aquatic life about 50 million years ago in the early Eocene . Whales are closely related to the even-toed ungulates (Artiodactyla), both groups together form the taxon Cetartiodactyla . The populations of many whale species have declined significantly as a result of pollution , fishing and industrial whaling .

features

General

Besides manatees, whales are the only mammals that have fully adapted to life in the water. They are unable to survive on land. In stranded whales, the weight of the body compresses their lungs or breaks their ribs because the buoyancy of the water does not support them . Smaller whales die from heat stroke due to their good thermal insulation . The body of the whales is adapted to their habitat, but they still share essential characteristics with all other higher mammals ( Eutheria ):

The whales are among the largest animals that have ever lived on earth . The blue whale ( Balaenoptera musculus ) is the largest known animal in the history of the earth with a body length of up to 33 meters and a weight of up to 200 tons. The sperm whale ( Physeter macrocephalus ) is the largest predatory animal on earth. The smallest whale species, on the other hand, only reach a maximum body length of about 1.5 meters, such as the La Plata dolphin , the Hector dolphin and the California harbor porpoise .

Whales are also characterized by a life expectancy that is unusual for higher mammals . Some species, such as the bowhead whale ( Balaena mysticetus ), can reach an age of over 200 years. Based on the annual rings of the bony ear capsule , the age of the oldest known specimen, a male, could be determined to be 211 years at the time of his death.

External anatomy

Tail fin of a humpback whale

The body contour of the whale resembles that of large fish, which can be attributed to the way of life and the special conditions of the habitat ( convergence ). They have a streamlined shape, and their front extremities are transformed into fins ( flippers ). They carry another fin on their back, which is called a fin and takes on different shapes depending on the species. In a few species it is completely absent. Both the flipper and the fin serve only to stabilize the whales in the water and to control them. The tail ends in a large caudal fin called the fluke and, like the fin, is a cartilaginous surface without bone parts. The fluke starts horizontally instead of vertically on the body, a distinguishing feature from the fish that is easily recognizable from the outside. It enables movement by striking vertically.

The whales completely lack their hind legs, as well as all other body appendages that could hinder the streamlined shape, such as the ears and hair. The male genitals and the mammary glands of the female are sunk into the body.

All whales have an elongated head, which, especially in the baleen whales, takes on extreme dimensions due to the wide jaws . The whale's nostrils form the blowhole, one in toothed whales and two in baleen whales. They lie on the top of the head so that the body can stay submerged while breathing. When you exhale, the moisture in the air you breathe usually condenses and forms the so-called bubble . In toothed whales, there is a connective tissue melon as the head arch. This is filled with air sacs and fat and helps with buoyancy and sound generation. The sperm whales have a particularly distinctive melon ; here it is referred to as the spermacetiorgan and contains the eponymous spermaceti or whale rat . The jaws of the toothed whales contain different numbers of teeth, from two flat tusks in the two- toothed whales to a large number of uniform (homodontic) teeth in the dolphins . The long tusk of the male narwhal is also a remodeled canine. The baleen whales are sitting in the upper jaw instead of teeth long-horned filter plates Barten .

The body is wrapped in a thick layer of fat, the so-called blubber . This is used for thermal insulation and gives the whales a smooth, streamlined body shape. In the large species, the bubbler can reach a thickness of half a meter. The very special structure of the skin above the layer of fat creates a phenomenon known as Gray's paradox : the body, especially of faster swimmers, such as dolphins, actually has far better flow properties than a solid body with the same shape the case is. This is attributed to the skin's cushioning properties, which alleviate the disturbing vortex formations . For this purpose, the dermis (corium or dermis) has long papillae that form a seam and are interlocked with the epidermis above . The papillae of the dermis sit on lamellae, which are largely positioned transversely to the longitudinal axis of the body and thus also to the direction of flow. Because of their length, the papillae were initially thought to be the ducts of sweat glands . Today, however, we know their real function and also know that whales have no skin glands with the exception of the mammary glands. In addition to these damping structures, the skin has a microscopically fine relief pattern. Based on the results of physiological experiments, an active reaction of the skin is also assumed. The optimization of the flow properties could be simulated in experiments with artificial whale skin.

skeleton

Exposed skeleton of a blue whale in front of the Long Marine Laboratory in Santa Cruz, California
Weathered brain skull with upper jaw of a toothed whale ( sperm whale ) in Kongsmark on Rømø , Denmark

The whale skeleton is largely without compact bones, as it is stabilized by the water. For this reason, the compact bones common in land mammals have been replaced by fine-meshed cancellous bones. These are lighter and more elastic. In many places, bone elements have also been replaced by cartilage and even fatty tissue , which further improves the hydrostatic properties of the whale's body. In the ear and on the muzzle there is a bone shape with extremely high density that is only found in whales , reminiscent of porcelain . This has special acoustic properties and conducts sound better than other bones.

Skull of a baleen whale
Baleen whale skeleton (without whales)

The skull of all whales is characteristically elongated, which can be seen in the baleen whale depicted here. The jaw and nasal bones form a protruding rostrum . The nostrils are at the apex of the head above the eyes . The back part of the skull with the brain skull is clearly shortened and deformed. By moving the nostrils to the top of the head, the nasal passages run vertically through the skull. In the toothed whales the larynx extends like a beak into this passage, in the baleen whales it gives way to the side of the passage. The teeth or beards in the upper jaw sit exclusively on the maxillary bone . The cerebral skull is narrowed towards the front by the nasal passage and is correspondingly higher, with individual cranial bones pushing one another (telescoping). The bony ear capsule, the petrosum , is only cartilaginously connected to the skull so that it can vibrate independently of it. For this reason, isolated ear capsules are common whale fossils known as cetolites . In many toothed whales, the skull is also asymmetrical due to the formation of a large melon and several air sacs.

The number of vertebrae in the spine is between 40 and 93 individual vertebrae , depending on the type. As in almost all mammals (exceptions: sloths and manatees ), the cervical spine consists of seven vertebrae, which in most whales are, however, greatly shortened or fused together, which provides stability when swimming at the expense of mobility. The ribs are supported by the thoracic vertebrae, the number of which can be from 9 to 17. The sternum is only cartilaginous and severely receded. The last two to three pairs of ribs are not connected to the sternum in all whales and are exposed as flesh ribs in the body wall; in the baleen whales all ribs are exposed with the exception of the first pair. This is followed by the stable lumbar and tail parts of the spine, to which all other vertebrae belong. Below the caudal vertebrae, the chevron bones have developed from the hemal arches of the vertebrae, which provide additional points of attachment for the tail muscles.

The front limbs are paddle-shaped with shortened arm and finger bones elongated to aid locomotion. They are fused together by cartilage. On the second and third fingers there is also an increase in the number of phalanges, a so-called hyperphalangia . The only functional joint is the shoulder joint , all others are immobile (except for the Amazon river dolphins ( Inia )). One collarbone is completely missing. Since it is no longer necessary for the whale to move on land and would no longer be possible for the large species due to their body weight, the hind limbs are severely stunted and only present as skeletal trudiments without any connection to the spine.

Internal anatomy and physiology

The structure of the respiratory and circulatory systems is particularly important for the whale's way of life in the water. The oxygen balance of the whales is accordingly highly effective. With each breath, a whale can exchange up to 90 percent of the total air volume in its lungs; in a land mammal, this value is around 15 percent. In the lungs, about twice as much oxygen is withdrawn from the inhaled air by the lung tissue as in a land mammal. The lungs themselves contain a double capillary network in the alveoli . In addition to the blood and the lungs, oxygen is stored in various tissues of the whales, especially in the muscles , in which the muscle pigment myoglobin ensures effective binding. This oxygen storage outside the lungs is vital for deep diving, as the lung tissue is almost completely compressed by the water pressure from a depth of around 100 meters. During the diving process, the oxygen consumption is massively reduced by lowering the cardiac activity and blood circulation; individual organs are not supplied with oxygen during this time. Some furrow whales can dive for up to 40 minutes, sperm whales between 60 and 90 minutes and duck whales even two hours. The diving depths are on average around 100 meters, sperm whales dive up to 3000 meters deep.

The whale's stomach consists of three chambers. The first area is formed by a glandless and very muscular forestomach (which is missing in beaked whales ), followed by the main stomach and the pyloric stomach, both of which are equipped with glands for digestion (see ruminants, there animals with a similar digestive system ). A bowel is attached to the stomachs, the individual sections of which can only be differentiated histologically . The liver is very large and has no gallbladder .

The kidneys are very flattened and very long. They are divided into several thousand individual lobules (reniculi) in order to be able to work effectively. The concentration of salt in the blood of whales is lower than that in seawater; the kidneys therefore also serve to excrete salt. This enables the whales to drink sea water.

Similarities in Chromosome Genetics

The original karyotype of the whales contains a chromosome set of 2n = 44. They have four pairs of telocentric chromosomes (chromosomes whose centromere is on one of the telomeres ), two to four pairs of subtelocentric and one to two large pairs of submetacentric chromosomes. The other chromosomes are metacentric - that is, have the centromere roughly in the middle - and are rather small. In the sperm whales (Physeteridae), the beaked whales (Ziphiidae) and the right whales (Balaenidae) there was a convergent reduction in the number of chromosomes to 2n = 42.

distribution and habitat

Killer whale in the arctic

Whales are mainly marine animals and can be found in all seas of the world. Some species swim into the river delta and even into the rivers. Only a few species, however, live exclusively in freshwater, there are several species of different families known as river dolphins. While many marine species of whales such as the blue whale , the humpback whale and also the killer whale have a distribution area that includes almost all seas, there are also individual species that only occur locally. These include, for example, the California harbor porpoise in a small part of the Gulf of California and the Hector's dolphin in individual coastal waters near New Zealand . In the seas there are both species that prefer the deeper sea areas and species that often or exclusively live near the coast and in shallow water areas.

The distribution of the habitats normally results from certain temperature limits in the oceans, and accordingly the distribution areas of most species lie along specific latitudes . Many species only live in tropical or subtropical waters, such as the Bryde's whale or the round-headed dolphin , others are only found in the southern (such as the southern smooth dolphin or the hourglass dolphin ) or northern polar sea (the narwhal and the white whale ). This vertical expansion is mainly interrupted by land masses acting as natural barriers. Individual populations of many cosmopolitan species exist in the Pacific , Atlantic and Indian Oceans , and some species only occur in one of these three separate oceans. For example, the Sowerby two-toothed whale and the Clymene dolphin are only found in the Atlantic, the white-stripe dolphin and the northern smooth dolphin only in the North Pacific. In migratory species, whose breeding grounds are often in tropical regions and whose foraging grounds are in polar regions, there is also the formation of southern and northern populations in both the Atlantic and the Pacific, which are genetically separated from each other by migration. For some species, this separation of populations ultimately leads to the formation of new species, such as the southern right whale and the two northern right whale species in the Atlantic and Pacific.

A total of 32 whale species have been identified in European waters, including 25 species belonging to the toothed whales and seven species belonging to the baleen whales.

Way of life

Social behavior

Most whales are extremely sociable animals with highly developed social behavior; only a few species live in pairs or as solitary animals. The whale groups, known as schools, usually consist of 10 to 50 animals, but on certain occasions (when there is a mass occurrence of food or during the mating season) the groups can also include well over 1000 animals. Socialization with other whale species is also possible.

Tail fin of a whale on the coast of Argentina

The individual schools have a fixed hierarchy, with the priority positions being determined by biting, pushing or ramming. The behavior in the group is only aggressive in extremely stressful situations such as lack of food and in captivity, usually the interaction is peaceful. Contact swimming, stroking and nudging each other play an important role. Also known are the playful behaviors of the animals, which are expressed in jumping in the air, somersaults, surfing or slapping fins and which also occur in adult animals.

To communicate with each other, the male animals emit song-like sounds and melodies ( whale song ) that can be heard over hundreds of kilometers in the water. Recent research has shown that every whale population develops its own typical song. Sometimes an individual whale can even be identified by its specific, unmistakable song, such as the 52-Hertz whale , which sings at a higher frequency than other whales. Some species of whale are capable of producing up to 622 different sounds. Comparisons of older with today's sound recordings show that the composition of sounds has changed or developed significantly over the years.

The whales also hunt in groups, often teaming up with other species. You can find many species of dolphins together with large tuna on hunting expeditions that follow large schools of fish. The killer whale ( Orcinus orca ) also hunts other, even larger whales in schools. Humpback whales ( Megaptera novaeangliae ) work together to form bubble carpets with which they delimit schools of small fish and krill and in which they emerge with their mouths open.

Reproduction and development

Most whale species have a seasonal reproductive cycle in which ovulation in the females coincides with the main activity of the testes in the males. This cycle is mostly coupled with seasonal migrations that can be observed in many species. Most toothed whales do not enter into firm ties when mating, and in many species the females have several partners during one season. The baleen whales, on the other hand, are largely monogamous within the individual reproductive periods, but they also do not enter into permanent ties.

The gestation period of the whales lasts between nine and 16 months, although the duration does not necessarily depend on the size. Harbor porpoises , like the giant blue whales, bear about 11 months. Whales usually give birth to only one young, and when twins are born, one young animal usually dies because the mother cannot produce enough milk for both young animals. In the case of the toothed whales, birth usually takes place with the tail first, so that the risk of drowning for the newborn is minimal, in the case of the baleen whales head first. After the birth process, the young animal is quickly transported to the surface for its first breath, with several conspecifics acting as "midwives" in many species. At birth, the young are about a third the size of the adults and are very quickly active on their own, comparable to the pups that flee from the nest or run-away pups of rural mammals. When suckling, the mother whale actively injects the milk with the help of the muscles of the mammary glands into the boy's mouth, as it has no lips to suckle. This milk usually has a very high fat content of 16 to 46 percent, which means that the young animals increase in size and weight very quickly.

The suckling period is usually long, it is around four months for many small cetaceans and often more than a year for large species, which is accompanied by a close bond between the mother and her offspring. In all whales, the mother animals are solely responsible for rearing the young, but some whale species have so-called "aunts" who occasionally suckle the young. Most whales mature late, typically seven to ten years old. This reproductive strategy produces few offspring that have a high survival rate. Here, too, there are faster species such as the La Plata dolphin , which is sexually mature at two years of age, but only lives around 20 years old. The sperm whale , on the other hand, only reaches sexual maturity at around 20 years of age, but can live between 50 and 100 years.

robber

Besides humans, most whale species have very few predators due to their size. Particularly noteworthy at this point are only larger sharks , which occasionally attack and kill smaller whale species, as well as other, mostly larger, toothed whales. Almost notorious in this context is the killer whale , which attacks almost all other small whales in addition to seals , penguins and other marine animals. In herd-like associations called schools , orcas also attack large baleen whales, mostly to prey on the juveniles swimming with them.

Whale carcasses as a habitat in the deep sea

Tales about "whale cemeteries", where the remains of dozen of dead whales are said to have accumulated, are - like the stories about " elephant cemeteries " - scientifically unsustainable. Nevertheless, the individual whale carcasses that have sunk into the deep sea represent important self-contained ecosystems on the ocean floor . Only recent, complex expeditions with the help of remote-controlled underwater vehicles ( ROVs ) have made taxonomic and ecological research on whale carcasses possible. About thirty animal species are currently known that appear to feed exclusively on whale carcasses. These include annelids such as the Osedax species.

It is possible that the impact of the huge whales on the ocean floor and the resulting pressure waves are a signal for many animal species to seek out the carcass. Sharks and predatory fish are some of the first visitors . Hagfish find their way along a chemical “scent trail” that is spread by ocean currents.

The decomposition of the fat and meat of the whales takes at least a year and is accompanied by a series of different communities. The fat-rich bones of whales can also serve as energy suppliers for several years. Specialized bacteria and archaea , which can carry out chemosynthesis in the lightless deep sea with the help of the hydrogen sulfide produced by the decomposition , are the basis for the nutrition of mussels and crabs.

Evolution of the whales

Relationships and phylogenetic development

Comparison of the skeleton of Dorudon atrox and the Protocetidae Maiacetus inuus in swimming position. The 2.6 m long Maiacetus comes from the early Middle Eocene of Pakistan

For a long time, paleontologists had believed, because of the similar nature of the skull and teeth, that the ancestors of the whales were the Mesonychia , a group of carnivorous ungulates with a controversial systematic position. Later it came to studies in the fields of molecular biology and immunology , which showed that the whales phylogenetically closely with the even-toed ungulates are related (Artiodactyla). The evolution of the whales began in the early Eocene , more than 50 million years ago, with early cloven-hoofed animals.

Fossil finds at the beginning of the 21st century have confirmed this. The most noticeable common trait shared by whales and cloven-hoofed animals involves the talus (astragalus), a bone in the upper ankle (ankle). In the early whales, it is characterized by double joint rollers ("rolling legs"), an anatomical feature that otherwise only appears in the ungulates. Corresponding finds have been made from the early Eocene deposits of the Tethys Sea in northern India and Pakistan . During this time, the Tethys Sea stretched as a shallow sea between the Asian continent and the northbound Indian plate .

According to most molecular biological findings, the hippos are the closest living relatives ( sister group ) of the whales. Some common anatomical features speak in favor of this view, for example similarities in the morphology of the posterior molars . The fossil record cannot substantiate this suspected relationship, however, because the oldest known fossil records of the hippopotamus only date back about 15 million years. The oldest whale fossils, however, are around 50 million years old.

In 2007 a group around the paleontologist Hans Thewissen created an alternative family tree. According to this, the closest relatives of the early whales were the Raoellidae , an extinct group of ungulates. Both taxa therefore together form the sister group of the remaining ungulates including the hippos:

 
 Cetartiodactyla  

 remaining ungulates


  NN  

 Raoellidae ( Indohyus , Khirharia and others)


   

 Whales (cetacea)




The presumed close relationship is based, according to Thewissen, on features of the Raoelliden Indohyus . These are primarily the bony ring on the temporal bone (bulla), the involucrum , a skull characteristic that was known previously only of whales, as well as other features of the Vorbackenzähne (premolars) and the bone structure.

With the help of the fossil record, the gradual transition from land to aquatic life can be traced. The regression of the hind legs allowed the spine to be more flexible. This made it possible for whales to move in the water with the vertical tail flapping. The front legs turned into fins and lost their original mobility.

The ear of today's whales is no longer open to the outside, the nostrils migrated from the tip of the head near the mouth opening upwards, so that the whale can breathe through the dorsal blowhole "while swimming past" . While the ancestors of the whales on the land had teeth divided into incisors, canines and molars, the teeth of the whale were similar to one another, which makes it easier for fish to eat (transition from heterodontics to homodontics ). A special and relatively late development occurred in the baleen whales: they got beards , which are structures of a horn-like protein.

Transition from land to sea

Fossil of a Maiacetus (red, skull beige) with fetus (blue, teeth red) shortly before the end of gestation . The cranial position of the young animal documents a birth process of the whales, which is still bound to the land, in this early phase of their evolution.

The reason for the dramatic change in habitat was, at least in part, the severe climate change in the Eocene . The rise in temperature caused droughts. The consequent lack of adequate nutrition affected herbivores and indirectly carnivores. As a result of the warming, the water level rose up to five meters; the seas offered coastal residents an alternative.

Transitional forms

One of the oldest representatives of the early whales ( Archaeoceti ) was Pakicetus in the Lower Eocene approximately 50 million years ago. The approximately wolf-sized animal, the skeleton of which is only partially known, (still) had functional legs and lived near the shore. His well-developed roll leg also suggests an archaeocete who was able to move around on land. Its long snout shows original, carnivorous teeth . Accordingly, in early attempts at reconstruction , Pakicetus is shown as an amphibious predator .

The most important form of transition from land to marine life is the 49 million year old Ambulocetus ("walking whale") discovered in Pakistan , which was up to three meters long. The limbs of this archaeocete were adapted for swimming, but locomotion on land was still possible. There he moved in a hunched position and probably crawled like a seal . Its muzzle was elongated, with nostrils and eyes high up. The tails of the animals were very strong and supported the locomotion. Ambulocetus lived in mangroves in brackish water and fed in the riparian zone as predators of fish and other vertebrates. A little later, four-legged whales had reached South America , as the discovery of a partial skeleton of Peregocetus from the Paracas formation in Peru shows. The remains indicate an animal about four meters long that lived amphibiously. They date to around 42.6 million years ago in the Middle Eocene. Presumably the early whales reached the South American continent via Africa . Whales first appeared in North America a good 41.2 million years ago.

From around 45 million years ago, other species such as Indocetus , Kutchicetus , Rodhocetus and Andrewsiphius were discovered that were clearly adapted to life in water. The hind legs of these species were already severely reduced and the body shape is reminiscent of that of seals . Rodhocetus , a member of the Protocetidae , is considered to be the first " ocean-going " whale. His body was streamlined and he had developed rangy and extended hand and foot bones, between which probably a webbed was tense. The lumbar spine , which was fused in the pelvic area of ​​land mammals, consisted of loose individual bones, which made it possible to support the swimming movement of the trunk and tail. So he was a good swimmer, but on land it was likely that he could only move with difficulty.

Inhabitants of the oceans

Since the late Eocene, about 40 million years ago, whale species that were no longer connected to the land have populated the sea, such as the up to 18 meters long Basilosaurus (formerly known as Zeuglodon ). The transition from land to water was thus completed within about 10 million years. In the Egyptian Wadi al-Hitan ("Valley of the Whales", also "Wadi Zeuglodon") numerous skeletons of Basilosaurus and other marine land vertebrates have been preserved.

Living reconstruction of Dorudon atrox from the late Eocene of Egypt

The direct ancestors of today's whales are likely to be found within the Dorudontidae , whose most famous representative Dorudon lived at the same time as Basilosaurus . Both groups had already developed the hearing typical of today's whales, which shows clear adaptations to life in water, such as the solid bulla that replaces the eardrum of land mammals, as well as sound-conducting elements for directional hearing underwater. The wrists of these animals were stiff and probably already wore the flippers typical of today's whales . The hind legs were also still there, but significantly reduced in size and connected to a stunted pelvis .

Many different forms of whale appeared in the period that followed. Today fossils of around 1000 species are known, the majority of which have disappeared, but whose descendants now populate all oceans.

Systematics

1. Bowhead whale, 2. Orca (killer whale), 3. Northern right whale, 4. Sperm whale, 5. Narwhal, 6. Blue whale, 7. Furrow whale, 8. Beluga whale (white whale). All whales are drawn to the same scale.

The order Cetacea is classically divided into two sub-orders:

  • Baleen whales (Mysticeti) owe their name to the whales , comb-like horn plates with frayed ends, with which the whales filter small animals such as plankton from the seawater by taking a large amount of seawater into their mouths and squeezing it through the whales . The whale of the bowhead whale can be over four meters long. The largest living animals belong to this group.
  • Toothed whales (Odontoceti), which also include dolphins , have a series of conical teeth in both jaws (e.g. dolphins) or only in the lower jaw, e.g. in the case of the sperm whale or the beaked whale . Toothed whales are characterized by the ability to perceive their surroundings by means of echolocation .

While there were still opinions until the 1970s that toothed and baleen whales developed independently of one another due to differences in body structure, skull and lifestyle, today we assume a common ancestor and consider the whales to be monophyletic . This assumption is supported by a number of new, common features of all whales ( synapomorphies ), above all the typical structure of the ear capsule and also the brain, as well as the fossil finds that allow a return of all whales living today to a common parent group.


The following cladogram shows the relationships between the main group representatives of the whales and the extinct whales according to Gatesy et al. 2013:


  Whales  






 Toothed whales and baleen whales


   

 Basilosaurus  †



   

 Dorudon †



   

 Rodhocetus †



   

 Remingtonocetidae †



   

 Ambulocetidae †



   

 Pakicetidae †



   

 Raoellidae †



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The following cladogram shows the relationships between toothed and baleen whales according to Gatesy et al. 2013:


  Toothed whales  




 La Plata Dolphin (Pontoporiidae)


   

 Amazon River Dolphins (Iniidae)


   

 Delphinoidea  ( dolphins , porpoises  and  gudgeon whales )


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 Beaked whales (Ziphiidae)



   

 Ganges dolphins (Platanistidae)



   

 Pygmy Sperm whales (Kogiidae)


   

 Sperm whales (Physeteridae)




  Baleen whales  




 Furrow whales (Balaenopteridae)


   

 Gray whales (Eschrichtiidae)



   

 Neobalaeninae



   

 Right whales (Balaenidae)



   

 Janjucetus †




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According to the classic system, the whales (Cetacea) are classified at the species level as follows:

Order whales (Cetacea)

Thirteen species of whales are known as large whales . However, this is not a systematic category, but a comprehensive term for the colossi of the various whale families.

In the article Systematics of the whales there is a comparison of the distribution area, the frequency and threat, as well as the size of the different species.

Whale strandings

Humans and whales

Word origin

The origin of the German word "Wal" can be clearly traced back to the Germanic , whose daughter languages derive the name ( Dutch walvis , English whale , Swedish val , Icelandic hvalur ) from the Germanic root * hwalaz , on which the word " catfish " is based . Names for marine and sea animals are difficult to compare within the Indo-European languages . Meanwhile, a connection to the Romance ( Latin squalus "sea fish") or Baltic branch ( old Prussian kalis "catfish") is suspected . However, it is also possible that it is a borrowing from a non-Indo-European language from (early) Germanic times.

The word "Walfisch" is proven in Old High German and is used in Middle High German and Middle Low German . Grimm's dictionary interprets it as a "clarifying composition" (compared to the older word "whale", which at that time was probably no longer clearly understandable in its meaning).

Research history

Whale sculpture in front of a natural history museum

In antiquity, whales were assigned to fish by Aristotle (4th century BC) due to their external appearance, although Aristotle was already able to determine many physiological and anatomical similarities with the terrestrial vertebrates, such as blood (circulation), lungs, uterus and fin anatomy. Its detailed descriptions were adopted by the Romans, but the content was mixed with the knowledge about the dolphins. Above all, Pliny the Elder should be mentioned here, who wrote a comprehensive natural history . This intermingling can also be found in the art of this and subsequent times. Since then, dolphins have been depicted with a high arched head typical of porpoises and a long snout typical of dolphins. The harbor porpoise is next to the dolphins one of the earliest accessible whales for research, as it could be observed from the land as a resident of the flat coastal areas of Europe. A large part of the knowledge that applies to the entirety of whales or toothed whales was first obtained from porpoises. One of the first anatomical descriptions of the whale's airways based on a porpoise comes from the year 1671 by John Ray , who nevertheless assigned the porpoise to the fish, as has been customary since Aristotle.

“The tube in the head through which this species of fish draws its breath and spits water lies in front of the brain and ends on the outside in a simple hole, but on the inside it is divided by a bony septum as if it were two nostrils; but underneath it opens up again in the mouth in a cavity. "

In 1693, John Ray first separated the subordinate baleen whales and toothed whales. It was not until Carl von Linné that a whale was assigned to mammals for the first time in 1758 with the porpoise.

threat

With a few exceptions, the threat to the whales comes directly from humans. The threats posed by humans can be divided into direct hunting by whaling and indirect hazards such as fishing and environmental pollution.

Products made from a whale

whaling

Whaling in the Arctic Ocean, graphic from around 1792
Whale bone domino from a whaling ship

In the Middle Ages the reasons for whaling, the enormous amounts of meat, the usable as fuel were whale and the jawbone, which was used in house construction. At the end of the Middle Ages, entire fleets were already going out to hunt the large whales, mostly right whales such as the bowhead whale . The Dutch fleet, for example, owned around 300 whaling ships with 18,000 men in the 16th and 17th centuries.

In the 18th and 19th centuries, especially baleen whales were hunted to the needs of the corset and crinoline manufacturer of whalebone cover. In addition, the spermaceti of the sperm whales served as a lubricant for machines and the ambergris as a raw material for the pharmaceutical industry and for perfume production. When the explosive harpoon was invented and used in the second half of the 19th century , there was a massive increase in the number of whales shot.

Large ships were converted into mother ships for whale processing and supplied with steam-powered fishing fleets. Around the first half of the 20th century, whales were very important as suppliers of raw materials for industry. Hunting was intense during this period, with over 30,000 whales being killed each year in the 1930s. A further increase to over 40,000 animals per year took place until the 1960s, which caused the populations of large baleen whale species in particular to collapse.

Most of the whale species hunted are threatened today. In the case of some species of large whales, the populations were exploited to the point of extinction. Today they are severely decimated as growth is only possible slowly. Were completely eradicated already the Atlantic and the Korean gray whale , the Atlantic right whales are expected today with about 300 to 600 animals, the Blauwalbestand is probably a maximum of 14,000 animals.

The first efforts to protect the whales were made in 1931. Particularly endangered species such as the humpback whale , which at that time still numbered around 100 animals, were placed under international protection, and the first protection zones were established. In 1946 the International Whaling Commission was founded to control and secure the stocks of whales. The killing of whales for commercial purposes was banned worldwide by this organization until 2005. However, whales are still hunted today. Japanese whaling ships in particular hunt whales of various species for ostensibly scientific purposes. Greenland and some indigenous peoples of the world are allowed to whale for traditional reasons and to ensure their survival. Iceland and Norway do not recognize the ban and operate open commercial whaling. Countries like Norway and Japan are pushing for an end to the moratorium.

fishing

Even the small whales that are of no interest for whaling - especially some species of dolphins  - are in some cases severely decimated. They very often fall victim to the tuna fishery because they often stay near schools of tuna. This is also known to fishermen, which is why they often look out for dolphins to catch tuna. Dolphins are much easier to spot than tuna because they regularly have to take a breath on the surface. The fishermen pull hundreds of meters in circles around the dolphin groups with their nets in the expectation that they will also enclose a school of tuna. The nets are pulled together, the dolphins get caught under the water and drown. Line fishing in larger rivers is particularly dangerous for river dolphins.

A far greater threat than bycatch , however, arises from targeted hunting for small whales. In the Southeast Asian region, they are sold to the local population in poorer countries as a fish substitute, since the real food fish of the region promise higher exports. In the Mediterranean, small whales are pursued as food competitors: Since the metabolism of marine mammals has a much higher energy requirement than predatory fish, they are deliberately destroyed in order not to have to share the stocks of edible fish with them.

Environmental hazards

Increasing marine pollution is a serious problem for marine mammals as well . Heavy metals , the remains of many plant and insect toxins and plastic debris from the flotsam are not biodegradable. They then enter the body of the whale when they eat directly or via the marine plants and prey. As a result, the animals are more susceptible to disease and have fewer offspring.

The destruction of the ozone layer also affects the whales, because plankton is very sensitive to radiation and does not reproduce as strongly. As a result, the food supply for many marine animals is shrinking, but the baleen whales are particularly affected. In addition to the intensive fishing, the nekton is also damaged by the more intensive UV radiation and, as a source of food, is limited in quantity and quality.

Over- acidification of the oceans through increased uptake of carbon dioxide (CO 2 ) can represent similar effects, at least in the long term , an effect which counteracts global warming , since it again takes away carbon from the warming atmosphere. CO 2 reacts with the water to form carbonic acid . The acidic water disrupts the building of the calcareous skeletons of various algae and microorganisms. Whales depend on this plankton, as it is the main food source for many species.

The military in particular makes use of powerful sonars , while the oil industry and marine mining also use artificial seismic sources (so-called airguns), powerful pumps and explosions, which, together with general shipping, increasingly result in noise in the oceans. Marine mammals that use biosonars for orientation and communication are not only hindered, but also regularly caused to panic. This causes gases bound in the blood to bubble out, whereupon the animal dies because the vessels are blocked, so-called decompression accidents (known in humans as a "serious diving accident"). Serious injuries also occur again and again when they come into contact with propellers .

After marine exercises with the use of sonar, dead whales with gas bubbles in their vessels are regularly washed up. The sound goes very far and develops its fateful effect within a hundred kilometers. Depending on the frequencies used , different species are more or less affected. The requirement is made that, before extensive use of sonar technology, it must first be excluded, if necessary also with sonar, that there are many marine mammals in the vicinity.

Cultural meaning

Whales play a major role in the culture of people living near the sea and islands. It is mainly small whales such as dolphins and porpoises that could be observed more intensively and thus entered the mythology of these peoples. Large whales, on the other hand, were mainly known for beaching whales (especially sperm whales) or they were described by seafarers.

Prehistoric times

Rock carvings from the Stone Age , such as those found in Roddoy and Reppa ( Norway ), show that the animals were also known to early cultures. Whale bones have been used for numerous purposes. In the Neolithic settlement of Skara Brae on Orkney , pots and pans were made from vortices. Some of the vessels contain traces of paint, Childe interprets them as paint buckets. A whale bone bowl comes from Foshigarry in Scotland.

antiquity

The Annihilation of Leviathan , wood engraving from the illustrated Bible by Gustave Doré , 1865

The whale was first mentioned by Homer among the ancient Greeks . Here it is called kétos , a term that initially included all large marine animals. The Latin name of the Romans for whale, cetus , was derived from this. Other names were phálaina ( Aristotle , Latin form ballaena ) for the female animal and, with an ironic style, musculus ( little mouse ) for the male animal. North Sea whales were called physeter , possibly referring specifically to the sperm whale (today Physeter catodon ). Whales are described in great detail by Aristotle, Pliny and Ambrosius . All mention both viviparity and the suckling of young animals. Pliny describes the spray tubes connected to the lungs, and Ambrosius even claims that whales take their young in their mouths for protection. Baleen whales are apparently only known to Aristotle.

Mythologically, whales are difficult to identify because they are equated with other large marine animals and monsters. It can be assumed, however, that the monster to which the vain Cassiopeia was to sacrifice her daughter Andromeda on behalf of the sea god Poseidon , who was finally saved by the hero Perseus , was a whale.

In the Bible , the Leviathan as a sea monster plays a role. The being unites features of a huge crocodile or a dragon and a whale , was created by God according to Ps 104.26  EU and is also to be destroyed again by him ( Ps 74.14  EU ; Isa 27.1  EU ). The Leviathan is described in more detail in the Book of Job ( Job 40.25  EU- 41.26).

The description of the prophet Jonah , on the other hand, is more clearly recognizable as a whale , who on his flight from the divine task of prophesying the city of Nineveh the downfall, is swallowed by a whale and spat out on the beach of Nineveh ( Jona 2: 1-11  EU ).

Silver coin with Taras riding a dolphin

In ancient times, dolphins are mentioned far more frequently than large whales. Aristotle devotes a larger space to the sacred animals of the Greeks in his historia animalium and goes into detail about their role as aquatic animals. The Greeks admired the dolphin as the "king of aquatic animals" and mistakenly called it a fish. His speed, his jumps, his intelligence and his low fear of people are praised. His mental faculties are felt both in his ability to escape fishermen's nets and in working with fishermen to fish.

River dolphins are known from the Ganges and - with a high probability wrongly - the Nile. The latter was evidently equated with sharks and catfish . Allegedly they even attacked crocodiles there. In the Black Sea the Thracians hunted dolphins to eat them and make oil from them.

Map of the constellation whale

Dolphins occupy some space in Greek mythology. Because of their intelligence, they saved people from drowning several times. Since they were said to have a special love for music - not least because of their own singing - they often saved famous singers like Arion from Lesbos from Methymna or Kairanos from Miletus in the legends . They were also known for their devotion to beautiful boys, some of whom they even went to death with. Because of their mental abilities, dolphins were thought to be people enchanted by the god Dionysus .

Dolphins belonged to Poseidon's retinue and brought his wife Amphitrite to him. But dolphins are also associated with other gods, such as Apollon , Dionysus and Aphrodite . The Greeks paid tribute to both the whale and the dolphin with their own constellation. The constellation of the whale ( Kétos , lat. Cetus ) is located south, the constellation of the dolphin ( Delphís , lat. Delphinus ) is located north of the zodiac.

There are often dolphin representations in ancient art. They were already represented by the Cretan Minoans . Later they were often found on reliefs , gems , lamps, coins , mosaics , tombstones, etc. A particularly popular depiction is that of Arion or Taras riding a dolphin . The dolphin is also a popular motif in early Christian art, not least because it was sometimes used as a symbol for Christ alongside the fish .

Middle Ages to the 19th century

Stranded sperm whale, depiction from 1598

In his travel story Navigatio Sancti Brendani , the Irish monk St. Brendan the Traveler described an encounter with a whale that he is said to have made between 565 and 573. There he described how he and his companions stepped onto a treeless island, which subsequently turned out to be a huge whale, which he called Jasconicus. They met this whale again seven years later and rested on its back.

Most of the descriptions of large whales from the time up to the whaling age from the 17th century onwards, however, came from stranded whales, which were not like any other known animal because of their corpulence and appearance. This was particularly the case for the sperm whale, which very often ends up in large groups. According to an evaluation of old documents by Raymond Gilmore from 1959, 17 sperm whales stranded in the mouth of the Elbe around 1723 and 31 animals on the coast of Great Britain in 1784. In 1827 a blue whale with a length of 28.5 meters drifted off the coast of Ostend , which at that time still belonged to the Netherlands , and was sent skeletonized through Europe for over seven years. During this time, other whales were shown around the world and attracted visitors as attractions of museums and traveling exhibitions.

La Baleine , depiction around 1840

Above all, the sailors of the whaling fleets of the 17th to 19th centuries provided more concrete and clear representations of the whales living in the wild, and the stories of whale watching led to stories that can largely be attributed to the seaman's thread . Although they were now aware that most whales are harmless giants, they described the fight with the harpooned animals as slaughter. With the intensification of whaling, so too did the descriptions of sea ​​monsters , which included giant whales, sharks , sea ​​snakes, and giant squids and octopuses .

One of the first whalers to describe their experiences on whaling voyages was the British captain Wilhelm Scoresby , who published the book Northern Whale Fishery in 1820 and described the hunt for the great baleen whales of the northern seas. In 1835 Thomas Beale , a British surgeon, followed with the book Some observations on the natural history of the sperm whale and in 1840 Frederick Debell Bennett with the story of a whale hunt… . The whales found their way into narrative literature and painting, especially in the novels Moby-Dick by Herman Melville and 20,000 Leagues Under the Sea by Jules Verne . In the 1882 children's book Adventures of Pinocchio by Carlo Collodi , however, no Wal occurs, although this is generally assumed. The wooden figure Pinocchio and its creator Geppetto were devoured by a shark in the novel. In Otto Julius Bierbaum's 1905, free retelling of the Pinocchio story, Gäpfel Kerns Abenteuer , the Marionette Gäpfel Kern and her father Pflaume are devoured by a whale. It was not until the Pinocchio film released by the Walt Disney Studios in 1940 that the shark in the Pinocchio story also became a huge, vicious whale.

Fence made from the lower jaw bones of baleen whales on Rømø

Whale bones were also used as raw material in historical times. Sometimes only individual parts of the vessel consisted of whale bones, such as the bottom of a bucket in the Scottish National Museum in Edinburgh . A whale chair seat comes from Howmae . In the Viking Age , ornate plates were made from whale bones, which are sometimes interpreted as ironing boards .

In the Canadian Arctic (east coast), sperm whale bones were used for house construction in the Punuk and Thule cultures (1000–1600 AD). In the absence of wood, they served as roof supports for the winter houses, which were half sunk into the ground. The actual roof was probably made of fur covered with earth and moss.

Modern culture

Bottlenose dolphin ( Tursiops truncatus )

Unlike in previous centuries, whales were no longer viewed as sea monsters and dangerous beasts in the 20th century. With their increasing exploration, they were gradually seen more and more as intelligent and peaceful animals that humans hunted and killed for no reason. The dolphins in particular were given this role above all others, and this is also reflected in films and novels from the 1960s to 1990s. For example, the main character in the Flipper series , a bottlenose dolphin , became a symbol of animal intelligence alongside other animal heroes such as Rin Tin Tin , Lassie and Fury from 1962 . This motif was also taken up in the series SeaQuest DSV (1993-1996), the Walt Disney film Free Willy - Call of Freedom (1993) and the book series The Hitchhiker's Guide to the Galaxy by Douglas Adams, as well as in many other films and books.

The reputation of the big whales, until then mainly characterized by the Moby-Dick films, also changed drastically. Since the 20th century, the animals have been regarded as "gentle giants" that have been very transfigured and roam the seas peacefully. Above all, the research into whale song led to an increasingly stronger positioning in the area of esotericism , which still uses the chants as relaxing meditation music today . In the movie Star Trek IV: Back to the Present , humpback whales and their song represent the only salvation for mankind. The asteroid (2089) Cetacea was named after the scientific name of the whale.

Sound recordings

See also

Systematics of the whales , Article contains a detailed list of all whales with further information

literature

  • Nigel Bonner: Whales of the World. Octopus Publishing, Blandfort 2002, ISBN 0-7137-2369-6 (non-technical, informative book).
  • T. Cahill: Dolphins. National Geographic, Washington DC 2003, ISBN 0-7922-3372-7 ( superb illustrated book ).
  • M. Carwardine: Whales and Dolphins in European Waters. Observe - Determine - Experience Delius Klasing, Bielefeld 2003, ISBN 3-7688-1456-4 .
  • M. Carwardine: Dolphins - Biology, Distribution, Observation in the Wild. Naturbuch Verlag, Augsburg 1996, ISBN 3-89440-226-1 .
  • M. Carwardine, E. Hoyt, RE Fordyce, P. Gill: Whales & Dolphins - the ultimate guide to marine mammals. HarperCollins, London 1998, ISBN 0-00-220105-4 (comprehensive picture guide).
  • P. Clapham: Whales. World Life Library. Colin Baxter Photography, Grantown-on-Spey 2001, ISBN 1-84107-095-5 .
  • A. Coenen: The whale book, whales and other marine animals as described by Adriaen Coenen in 1585. Reaction Books, London 2003, ISBN 1-86189-174-1 (excerpt from Coenen's manuscripts with true-to-color reproduced original illustrations (first illustrated whale - Representation of Europe) with translation into modern English and commentary on marine biology and historical background of Coenen).
  • Ralf Kiefner: whales and dolphins worldwide. Pacific Ocean, Indian Ocean, Red Sea, Atlantic Ocean, Caribbean, Arctic, Antarctica. Year Top Special, Hamburg 2002, ISBN 3-86132-620-5 (guide to the magazine “tauchen”, very detailed).
  • CC Kinze: Photographic Guide to the Marine Mammals of the North Atlantic. University Press, Oxford 2002, ISBN 0-19-852625-3 (science-oriented guide).
  • J. Mann, RC Connor, P. L Tyack, H. Whitehead (Eds.): Cetacean Societies - Field Studies of Dolphins and Whales. University of Chicago Press, Chicago 2000, ISBN 0-226-50340-2 .
  • T. Martin: Whales, Dolphins & Porpoises. World Life Library. Colin Baxter Photography, Grantown-on-Spey 2003, ISBN 1-84107-173-0 .
  • T. Nakamura: Dolphins. Chronicle Books, San Francisco Ca 1997, ISBN 0-8118-1621-4 (photo book).
  • J. Niethammer, F. Krapp (ed.): Handbook of mammals in Europe. Volume 6: Marine Mammals. Part 1B: Whales and Dolphins. 1. AULA, Wiesbaden 1994, ISBN 3-89104-559-X (very detailed specialist book).
  • RM Nowak: Walker's Marine Mammals of the World. Johns Hopkins University Press, Baltimore 2003, ISBN 0-8018-7343-6 (excerpt from the complete works).
  • RR Reeves, BS Stewart, PJ Clapham, JA Powell: Sea Mammals of the World - a complete Guide to Whales, Dolphins, Seals, Sea Lions and Sea Cows. A&C Black, London 2002, ISBN 0-7136-6334-0 (guide with numerous pictures).
  • Gérard Soury: The great book of the dolphins. Delius Klasing, Bielefeld 1997, ISBN 3-7688-1063-1 (detailed illustrated book).
  • B. Wilson: Dolphins. World Life Library. Colin Baxter Photography, Grantown-on-Spey 2002, ISBN 1-84107-163-3 (marine biology, personally shaped, numerous pictures, including river dolphins).
  • M. Würtz, N. Repetto: Underwater world. Dolphins and Whales. White Star Guides, Vercelli 2003, ISBN 88-8095-943-3 (identification book).

Web links

Commons : Whales (Cetacea)  - Collection of images, videos and audio files
Wiktionary: Whale  - explanations of meanings, word origins, synonyms, translations

Individual evidence

  1. ↑ a b c Cf. the entries "Wal" (vol. 27, col. 1068 f.) And "Walfisch" (vol. 27, col. 1221 ff.) In: German dictionary by Jacob and Wilhelm Grimm. Leipzig 1854–1961.
  2. ^ Entry "Walfisch" under Duden online .
  3. ↑ a b Aristotle : Historia Animalium , HA 566b2-5 (in the page numbering according to Bekker).
  4. ^ A b Aldemaro Romero: When whales became mammals: The scientific journey of Cetaceans from fish to mammals in the history of science (PDF). In: INTECH Open Access Publisher. 2012.
  5. ↑ GW Rouse, SK Goffredi, RC Vrijenhoek: Osedax: Bone-Eating Marine Worms with Dwarf Males. In: Science. 305, 2004, pp. 668-671.
  6. ↑ a b P. D. Gingerich, M. ul-Haq, W. von Koenigswald, WJ Sanders, BH Smith et al .: New Protocetid Whale from the Middle Eocene of Pakistan: Birth on Land, Precocial Development, and Sexual Dimorphism. In: PLoS ONE. 4 (2), 2009, p. E4366. doi: 10.1371 / journal.pone.0004366
  7. ↑ Michael J. Benton : Paleontology of the vertebrates . Publishing house Dr. Friedrich Pfeil, Munich 2007, p. 360.
  8. ↑ JGM Thewissen, Lisa Noelle Cooper, Mark T. Clementz, Sunil Bajpai, BN Tiwari: Whales orginated from aquatic artiodactyls in the Eocene epoch of India. ( Memento from May 25, 2010 in the Internet Archive ) In: Nature. 450, 2007, pp. 1190-1194. doi: 10.1038 / nature06343 , (Nature Video)
  9. ↑ JGM Thewissen: Phylogenetic aspects of Cetacean origins: A morphological perspective. In: Journal of Mammalian Evolution . 2 (3), 1994, pp. 157-184.
  10. ↑ Michael J. Benton: Paleontology of the vertebrates . Publishing house Dr. Friedrich Pfeil, Munich 2007, p. 365.
  11. ↑ Olivier Lambert, Giovanni Bianucci, Rodolfo Salas-Gismondi, Claudio Di Celma, Etienne Steurbaut, Mario Urbina and Christian de Muizon: An Amphibious Whale from the Middle Eocene of Peru Reveals Early South Pacific Dispersal of Quadrupedal Cetaceans. Current Biology 29, 2019, doi: 10.1016 / j.cub.2019.02.050
  12. ↑ a b John Gatesy, Jonathan H. Geisler, Joseph Chang, Carl Buell, Annalisa Berta, Robert W. Meredith, Mark S. Springer, Michael R. McGowen: A phylogenetic blueprint for a modern whale . In: Molecular Phylogenetics and Evolution. Volume 66, Issue 2, February 2013, pp. 479–506. doi: 10.1016 / j.ympev.2012.10.012
  13. ^ R. Ewan Fordyce, Felix G. Marx: The pygmy right whale Caperea marginata: the last of the cetotheres. In: Proc. R. Soc. B 22, Volume 280, No. 1753, February 2013, p. 20122645. doi: 10.1098 / rspb.2012.2645
  14. ↑ Tadasu K. Yamada, Shino Kitamura, Syuiti Abe, Yuko Tajima, Ayaka Matsuda, James G. Mead and Takashi F. Matsuishi. 2019. Description of A New Species of Beaked Whale (Berardius) found in the North Pacific. Scientific Reports. 9: 12723. nature.com/articles/s41598-019-46703-w
  15. ↑ Tomas Hrbek, Vera Maria Ferreira Da Silva, Nicole Dutra, Waleska Gravena, Anthony R. Martin, Izeni Pires Farias: A New Species of River Dolphin from Brazil or: How Little Do We Know Our Biodiversity. In: PLoS ONE . 9, 2014, p. e83623. doi: 10.1371 / journal.pone.0083623
  16. ↑ M. Ruiz-García, S. Caballero, M. Martinez-Agüero, JM Shostell: Molecular differentiation among Inia geoffrensis and Inia boliviensis (Iniidae, Cetacea) by means of nuclear intron sequences. In: VT Koven (Ed.): Population Genetics Research Progress. Nova Publishers, Boca Raton, FL, USA 2008, pp. 177-203.
  17. ^ Friedrich Kluge: Etymological dictionary of the German language. 24th edition. Edited by Elmar Seebold. De Gruyter, Berlin and New York 2002.
  18. ^ J. Ray : An account of the dissection of a porpess. In: Philosophical Transactions of the Royal Society of London. Volume 6, 1671, pp. 2274-2279.
  19. ↑ Susanne Prahl: Investigations into the construction of the epicranial airways in harbor porpoises (Phocoena phocoena Linnaeus, 1758). Dissertation to obtain the doctoral degree of the Department of Biology of the Faculty of Mathematics, Computer Science and Natural Sciences of the University of Hamburg, Hamburg 2007 (PDF cannot be linked due to blocking filter), p. 6.
  20. ↑ Injured whale redeemed through euthanasia. In: wochenblatt.es . April 25, 2019. Retrieved May 26, 2019 .
  21. ^ VG Childe: Skara Brae. A Pictish village in Orkney. Kegan, Paul, Trench, Trubner & Co., London 1931, Pl. LI
  22. ^ VG Childe: Skara Brae. A Pictish village in Orkney. Kegan, Paul, Trench, Trubner & Co., London 1931, Pl. L
  23. ^ BC Hood: The circumpolar zone. In: B. Cunliffe, C. Gosden, R. Joyce (Eds.): The Oxford Handbook of Archeology. Oxford University Press, Oxford, pp. 823 f.
  24. ^ A. McCartney: A processual Consideration of Thule Whale Bone Houses. In: A. McCartney (Ed.): Thule Eskimo Culture: An Anthropological Retrospective. (= Archaeological Survey of Canada Mercury Series. 88). National Museum of Man, Ottawa 1979, pp. 301-324; Peter C. Dawson, Richard M. Levy: A Three-Dimensional Model of a Thule Inuit Whale Bone House. In: Journal of Field Archeology. 30/4, 2005, pp. 443-455; JE Le Mouel, M. Le Mouel: Aspects of Early Thule Culture as seen in the Architecture of a Site on Victoria Island, Amundsen Gulf Area. In: Arctic. 55 (2), 2002, pp. 167-189.
  25. ^ J. Savelle: The Role of Architectural Utility in the Formation of Archaeological Whale Bone Assemblages. In: Journal of Archaeological Science. 24, 1997, pp. 869-885.

Remarks

  1. ↑ On the one hand, the whales are paraphyletic without the inclusion of the "dolphins" distributed over three families , on the other hand, the Delphinidae also include species that are traditionally referred to as whales (see systematics ).
This article was added to the list of excellent articles on April 19, 2006 in this version .