Why do fish not have a foreleg?



What do whales look like?

The body of the whale is streamlined and the front legs are transformed into fins. Most whale species also have a fin on their back, the so-called fin.

The individual species can be easily distinguished by their shape. However, some species, such as the sperm whale, do not have a fin.

The tail of the whale is transformed into a large caudal fin, the so-called fluke. It is used for locomotion. The fluke is aligned horizontally to the body and not perpendicular as in fish - for example in sharks.

The entire body of the whale is wrapped in a thick layer of fat, the bubble. It protects the animals from the cold. In large whales, the bubbler can be up to 50 centimeters thick.

The whale's head is elongated. This is particularly noticeable in the baleen whales, which have a very large head with huge jaws. The beards are housed in the jaw. These comb-like, fibrous horn plates form the filtering or filtering apparatus with which the animals filter the plankton out of the water. As their name suggests, toothed whales have teeth in their mouths.

The whale's nostrils are transformed into blowholes. Toothed whales only have one blowhole, baleen whales two. The blowholes are at the top of the head above the eyes. The whales exhale through these blowholes.

Toothed whales also show a typical bulge on their head, the so-called melon. It consists of air and fat and is used for buoyancy in the water and for the production of sounds. The whale's ears lie inside the head and are not open to the outside. The eyes are on the side of the head.

Where do whales live?

Whales can be found in all of the world's seas. Some species such as killer whales, blue whales or humpback whales colonize almost all seas, others only occur in certain areas. The Hector dolphin, for example, only lives on parts of the coast of New Zealand.

Almost all whales live in the sea. Exceptions are only a few river dolphin species that are at home in rivers, i.e. in fresh water. One example is the Amazon dolphin. Some whales live in shallow coastal waters, others in deep ocean zones. Some whales, such as the Bryde's whale, only live in tropical seas, while others, such as the narwhal, live in the Arctic Ocean. Many species of whale migrate: they give birth to their young in warm tropical seas. Then they move to the nutrient-rich polar seas to eat a thick layer of fat there.

What kinds of whales are there?

The ancestors of the whales were mammals living on the land, who transitioned to aquatic life around 50 million years ago and gradually evolved into perfect marine mammals. Scientists have found that whales are related to the ungulates. Your closest relative in the country is the hippo.

Today there are around 15 different baleen whales and 75 toothed whale species. 32 species of whales live in European seas. 25 are toothed whales, seven are baleen whales. The largest whale is the blue whale, the smallest whale species are dolphins, some of them measuring just 150 centimeters.

The following species are among the most famous whales:

The blue whale is the largest animal that has ever lived on earth. It grows up to 28 meters, sometimes even up to 33 meters, and weighs up to 200 tons. In comparison, elephants are almost lightweights: They only weigh up to five tons.

The blue whale lives in the North Atlantic, Pacific, Indian Ocean and Antarctica. The giant is endangered today, there are only about 4,000 animals left. Despite being so massive, the blue whale feeds on microscopic plankton, tiny crabs, and small fish that it filters out of the water. He can dive to a depth of 150 meters.

With a length of 18 to 23 meters and a weight of 30 to 60 tons, the fin whale is the second largest living animal. It can be found in all seas in the world and can dive up to 200 meters deep. He is very much at risk.

Humpback whales grow up to 15 meters long and weigh 15 to 20 tons. They live in the northern hemisphere in the Atlantic and Pacific as well as in the Indian Ocean. You can jump out of the water quite a long way.

The individual animals can be distinguished by the typical notches on their tail fluke. When they dive down from the surface, they curve the body into a hump, hence their name.

Gray whales grow to be 12 to 15 meters long and weigh 25 to 35 tons. They only occur in the Pacific. They cover up to 20,000 kilometers on their hikes.

Gray whales can often be seen near the coast. You can easily recognize them by the fact that their body is colonized by barnacles.

Killer whales are easy to recognize by their black and white body markings and the long fluke on their backs. They grow to be five to ten meters long and weigh three to ten tons.

They can be found in all seas, but they mostly live in cooler regions. Killer whales are excellent hunters and hunt fish, seals and smaller whales in groups. The best known is the "killer whale", also known as the orca.

The sperm whale is eleven to 20 meters long and weighs between 20 and 60 tons. It lives in the Atlantic, Pacific and Indian Oceans and is considered endangered. The animals can dive up to 3000 meters deep.

The beluga or white whale belongs to the family of the gudgeon whale and grows to three to six meters long. It lives in arctic and subarctic seas off the coasts of Russia, Canada and Alaska. Sometimes it migrates from the sea to the mouth of larger rivers.

The shape of the belugas is somewhat reminiscent of that of the dolphins, which also belong to the whales. Belugas can change their facial expressions to show whether they are excited or angry.

Its white color is striking. Newborn animals are gray to brown or black, at one year they turn blue-gray and only at the age of five their skin is white.

Belugas belong to the toothed whales and feed on fish, octopus, mussels and crustaceans. Because they live near the coast, they hunt mainly in shallow water down to a depth of ten meters.

Belugas are very sociable and live in groups of ten or more animals. During the breeding season, groups with sometimes several thousand animals gather in river estuaries. After fourteen and a half months of gestation, a female gives birth to one young each. It is suckled by the mother for about two years.

The animals can live up to 40 years. Their enemies include polar bears and killer whales.

How old do whales get?

The whale species get different ages. Dolphins like the La Plata dolphin live around 20 years, while sperm whales can live between 50 and 100 years.


How do whales live?

Whales, like all mammals, breathe with lungs and therefore have to go to the surface to breathe. But you can dive for a very long time. The range extends from a few minutes to 40 minutes. The sperm whale can even stay underwater for 60 to 90 minutes. Whales dive on average about 100 meters deep, sperm whales even up to 3000 meters.

Whales can swim quickly. The blue whale, for example, normally travels at 10 to 20 kilometers per hour, but reaches a speed of 50 kilometers per hour in the event of danger.

This is possible, among other things, because whales have a very powerful heart, which distributes the oxygen they take in very well in the body. In addition, they can exchange up to 90 percent of the air volume in their lungs with one breath. In a land mammal it is only 15 percent.

Whales take twice as much oxygen from the air they breathe as land mammals and they can store the oxygen better in their bodies. When diving, they also lower the heart rate and blood circulation so that they use less oxygen.

When whales exhale through their blowholes, they expel the air at high pressure. Due to the lower outside temperature, the moisture contained in the 37 degree warm air condenses. and a kind of fog fountain, the so-called blow, is created. In whales with two blowholes, the blowhole is often V-shaped. The blow of the sperm whale, which has only one blowhole, on the other hand, emerges at a 45-degree angle to the front left. In the case of the giant blue whale, the blow can be up to twelve meters high. You can therefore recognize some whales from a long distance by means of their blow.

Many whales are very sociable, they live in groups called schools. Other species live alone or form groups during the mating season, or they meet at certain times in nutrient-rich waters. Sociable whales such as dolphins or killer whales have very complex social behavior.

There is a hierarchy in the group. Most of the time the animals are peaceful, but they can also be aggressive with each other when they are stressed. It is fascinating to watch whales play: they nudge each other, hit the water with their fins or jump out of the water.

It is not clear why whales sometimes get stranded. This is most common with pilot and sperm whales. Researchers suspect various reasons: for example, the disturbance of the magnetic sense of the animals, injuries, infections and parasite infestation could also be reasons, or even poisoning of the animals through their food.

Many researchers see the noise from shipping, oil rigs and the sonar of military ships as the cause of the stranding of whales, as these disturb the animals' sense of direction and their communication.

It is also conceivable that whales follow weak or sick conspecifics into shallow water and then get stranded. Once a whale lies on the beach, it is usually crushed by its own body weight. In addition, the animals quickly overheat and die.

Friends and enemies of whales

Small species of whales can fall prey to large sharks. Large killer whales (orcas) also eat small species of whales. Killer whales in particular fall victim to young animals.

But the greatest enemy of the whales is humans. Many species were almost wiped out by hunting.

How do whales reproduce?

Males and females meet to mate, but form a pair for a maximum of one season. Most whales, however, have multiple partners. The gestation period lasts nine to 16 months, depending on the species. Whales, like all mammals, give birth to young animals that are already fully developed. Usually only one young is born. After the birth, the mother helps the boy to the surface of the water so that he can take his first breath there. In many species other conspecifics help the mother to look after the young.

Newborn whales are already very large, about a third the size of an adult animal. They are instantly very active and swim around. Since whale calves are initially suckled with their mother's very high-fat milk, they grow up quickly. The suckling period lasts four months to over a year, depending on the species.

Whales reach sexual maturity relatively late, usually between seven and ten years of age. The sperm whale does not become sexually mature until it is 20 years old.

How do whales hunt?

Toothed whales hunt fish and seals. Dolphins or killer whales sometimes hunt together in a group. Toothed whales can perceive their environment through echolocation. This helps them track down prey.

Humpback whales team up and use air bubbles to create a kind of curtain that they use to crowd together and contain schools of fish. Then they swim into the school from below with their mouths open and swallow the fish.

How do whales communicate?

Whales make sounds that can be heard in the ocean for hundreds of kilometers. These so-called chants differ from species to species, and the individual groups of a species also develop different chants - they speak literally different "dialects". Even individual animals can be recognized by their typical whale song.


What do whales eat?

Whales have completely different diets. The baleen whales use their whales to filter tiny plankton from the sea water by ingesting large amounts of water and pressing it out again through the whales. The toothed whales, as their name suggests, have teeth and live as predators. They hunt fish, but also smaller marine mammals such as seals and smaller whale species.

Keeping whales

Dolphins and killer whales are still kept in dolphinariums. Appropriate husbandry is not possible there - many animals suffer and die prematurely.

If you want to see whales, you should rather take part in a whale watching tour while on holiday and experience the animals in the wild. This is also possible in Europe, for example in Portugal, Spain or Norway.