The blue whale (vomited) is the most massive inhabitant of our planet. It weighs up to 170 tons, and its length can be up to 30 meters. Only a few representatives of this species grow to such sizes, but the rest can also rightfully be called giants. Due to active extermination, the vomit population has been greatly reduced, and now they are threatened with extinction.
Origin of the species and description
Photo: Blue Whale
Whales, like all other cetaceans, are not fish, but mammals, and are descended from terrestrial artiodactyls. Their external similarity with fish is the result of convergent evolution, in which organisms living in similar conditions, initially very different from each other, acquire more and more similar features over time.
Of the other modern animals, the closest thing to whales is not fish, but hippopotamuses. More than 50 million years have passed since their common ancestor lived on the planet – he lived on land. Then one of the species descended from it moved to the sea and gave rise to cetaceans.
Video: Blue whale
The scientific description of vomit was first given by R. Sibbald in 1694, and therefore it has long been called Sibbald's minke whale. The Latin name Balaenoptera musculus, which is still accepted today, was given by C. Linnaeus in 1758. Its first part is translated as “whale-winged”, and the second – “muscular” or “mouse”.
For a long time, the blue whale was hardly studied, and scientists had little idea even of how it looks: the drawings in the biological reference books of the century before last are incorrect. Only by the end of the century the species began to be systematically studied, at the same time its modern name, that is, the “blue whale” began to be used.
This species includes three subspecies:
- pygmy blue whale;
- northern;
- southern.
They differ quite a bit from each other. Dwarf vomits live in the warm Indian Ocean, while representatives of the other two subspecies like colder water and migrate to the Arctic or Antarctic in summer. Northern vomits are considered a typical subspecies, but southern ones are more numerous and larger.
The internal organs of the vomit match the size of its body – for example, its heart weighs 3 tons. A medium-sized room would fit in that whale's mouth.
Appearance and Features
Photo: Blue Whale Animal
The skin is gray, with spots. The shade of the back and sides is slightly lighter, while the head, on the contrary, is darker. The belly is distinctly yellowish, which is why the vomit was previously called the yellow-bellied whale. The modern name of the animal was given because its back can appear blue when viewed through sea water.
The skin is mostly smooth, but stripes run down the belly and throat. A lot of different parasites settle on the skin and whalebone of the animal. The eyes are small in relation to the body – only 10 centimeters in diameter, located at the edges of the horseshoe-shaped head.
The jaw is arched and protrudes forward by about 20 centimeters when the mouth is closed. Whales are warm-blooded, and an impressive layer of fat is called upon to help maintain the temperature.
There are no gills, the vomits breathe with the help of powerful lungs: almost complete air exchange can be carried out at a time – by 90% (for comparison: a person needs to take six breaths and exhalations to achieve this indicator).
Due to the volume of the lungs, whales can stay in the depths for up to 40 minutes before needing fresh air. When the whale rises to the surface and exhales, a fountain of warm air appears, and the sound made at the same time can be heard from afar – for 3-4 kilometers.
In total, in the mouth of the animal there are several hundred whalebone plates measuring 100 by 30 centimeters. With the help of plates, the vomit sips water, and the fringe with which they end filters out plankton from which the whale feeds.
Where does the blue whale live?
Photo: Great Blue Whale
Earlier to meet vomits it was possible in various parts of the world, but then their total number decreased significantly, and the range became broken. There are several zones in which this animal can now be found most often.
In summer, this is a belt of Arctic and Antarctic reservoirs. In winter, they travel closer to the equator. But they don’t like too warm water, and they almost never swim to the equator itself, even during migrations. But pygmy vomits live in the warm waters of the Indian Ocean all year round – they do not swim to cold seas at all.
The migratory routes of the vomit are still not fully understood, and one can only note where their presence has been recorded. Winter migration itself remained unexplained for a long time, because the food supply in the Arctic and Antarctic seas remains the same in winter. The most common explanation today is that this is required for cubs whose fat layer is insufficient to stay in cold waters in winter.
The most numerous groups of vomits are in the Southern Hemisphere, in the Northern Hemisphere they are much less common, but sometimes swim to the coast Portugal and Spain, met them even off the Greek coast, although they usually do not swim in the Mediterranean Sea. They can rarely be found off the coast of Russia.
Whale populations are distinguished (they are also called herds) – they almost do not mix with representatives of other populations, even if their ranges intersect. In the northern seas, researchers identify 9 or 10 populations; there are no such data on the southern seas.
What does the blue whale eat?
Photo: Sea blue whale
Their menu consists of:
- plankton;
- fish;
- squid.
Not a rich set, moreover, the basis of the diet is plankton, consisting mainly of krill. Depending on the region, these can be different types of crustaceans. As for fish, according to the majority of cetologists (as specialists involved in the study of cetaceans are called), it appears on the whale’s menu only by chance, getting there when swallowing crustaceans, but the whale does not eat it on purpose.
Some cetologists, however, believe that if the blue whale does not find large enough accumulations of plankton to satisfy its appetite, then quite deliberately swims up to schools of small fish and swallows them. The same thing happens with squid.
In any case, it is plankton that dominates in the diet of the vomit: the animal finds its accumulations, swims directly into them at a fairly high speed and absorbs tens of tons of water into its open mouth at once. When feeding, a lot of energy is spent, and therefore the whale needs to look for large accumulations of food – it does not react to small ones.
To be completely satiated, the blue whale needs to absorb 1-1.5 tons of food. In total, 3-4 tons are needed per day – for this, the animal filters a huge amount of water. For food, it dives to a depth of 80-150 meters – such dives are made regularly.
He vomited even more than the largest dinosaurs, the weight of which is approximately established by scientists. A specimen weighing 173 tons was recorded, which is 65 tons more than the estimated mass of the largest of the dinosaurs.
Character and lifestyle features
Photo: Blue whale in the ocean
Often they swim alone, and sometimes two or three. In areas rich in plankton, several such groups may gather. But even if the whales have huddled in a group, they still behave aloofly, and after a while they blur.
You cannot meet them close to the coast – they love vast expanses and depths. Most of the time they spend quietly swimming from one accumulation of plankton to another – this can be compared to how land herbivores graze.
On average, a blue whale swims at a speed of about 10 km/h, but it can swim faster – if it is frightened by something, it reaches 25-30 km/h, but only for a short time, because during such a race it spends a lot of energy .
The process of immersion for nutrition is interesting – it requires preparation. First, the whale empties its lungs, then takes a deep breath, dives shallowly about ten times and resurfaces, and only after that does a deep and long dive.
Usually the vomit goes a hundred or two meters deep in the water, but if he is frightened, he can dive much deeper – up to half a kilometer. This happens if killer whales hunt him. After 8-20 minutes, the whale emerges and begins to breathe rapidly, releasing fountains into the air.
After “catching his breath” in a few minutes, he can dive again. If a whale is chased, it can stay in the water column for much longer, up to 40-50 minutes, but gradually loses strength.
Social Structure and Reproduction
Photo: Blue whale calf
To communicate with other whales use powerful infrasonic signals with a frequency of about 10-20 Hz. With their help, vomits can make themselves known to relatives swimming at a considerable distance.
These animals are monogamous, and established pairs swim together for many years. Once every two years, a whale calf appears in such pairs – before that, the female bears it for almost a year. A newborn is fed with very fatty milk for a little more than six months, and on a milk diet adds a hundred kilograms daily.
As a result, it grows very quickly to an impressive size, reaching 20 tons, or even more weight. Vomits are fertile from the age of 4-5, but even after the onset of this period, the growth process continues – it goes up to 15 years.
Researchers' opinions on the life expectancy of vomits differ. The minimum estimate is 40 years, but according to other sources, they live twice as long, and centenarians even exceed a hundred years. Which estimate is closer to the truth has not yet been established for certain.
Bews are the loudest of living creatures. They are even louder than an airplane jet engine! Kindred can hear their songs hundreds or even thousands of kilometers away.
Natural enemies of blue whales
Photo: Blue whale
Because of their large size, only killer whales prey on them. Most of all they like the language of the whale. But they also attack only young or sick whales – an attempt to hunt a healthy one, for all its slowness, will not lead to anything good – the difference in mass is too great.
Even so, in order to defeat a whale, killer whales have to act in a group, sometimes of dozens of individuals. During the hunt, killer whales try to drive the victim into the water column, preventing them from rising and replenishing their air supply. As it ends, the whale weakens and resists more and more sluggishly, while killer whales are able to stay in the water longer. They attack the whale from different sides, tear off pieces from its body and thus weaken it, and then kill it.
But the damage from killer whales is not comparable to that caused to blue whales by people, therefore it was a person who could, without exaggeration, be called their main enemy, up to the ban on fishing. It is because of the active whaling that the vomit is endangered. From one such whale, you can get 25-30 tons of blubber, a valuable whalebone, from which many products were made, from brushes and corsets to carriage bodies and chairs, and their meat also has high palatability.
The extermination of blue whale began after the appearance of a harpoon gun in the second half of the century before last, after which it became possible to hunt for it much more efficiently. Its pace picked up after humans nearly wiped out the humpback whale, and blue has become a new source of blubber and baleen. Commercial production of vomit was stopped only in 1966.
Population and species status
Photo: Animal blue whale
Before the start of extermination by people, the population went to hundreds of thousands – according to various estimates, from 200,000 to 600,000 individuals. But due to intensive hunting, the number of vomits has been greatly reduced. How many of them are now on the planet exactly is a difficult question, and researchers' estimates vary greatly depending on the calculation methodology used.
The minimum estimate suggests that there are from 1,300 to 2,000 blue whales on the planet, of which in northern about 300 – 600 animals live in the seas. More optimistic researchers give figures of 3,000 – 4,000 for the northern seas and 6,000 – 10,000 for the southern ones.
In any case, their population has been severely undermined, as a result of which the vomit has been given the status of an endangered species (EN) and they are under protection. Commercial trapping is strictly prohibited, and poaching is also suppressed – punishments for notorious poachers have had an effect, and now cases of illegal catching of blue whales are rare.
Despite this, they are still under threat, and their population is recovering slowly in due to the complexity of reproduction and some other factors:
- pollution of ocean waters;
- an increase in the number of long smooth networks;
- collisions with ships.
These are all significant problems, for example, in a population of whales studied by scientists, 9% were found to have ship collision scars, and 12% had net marks. However, in recent years, a slight increase in the number of blue whales has been recorded, which gives hope for the conservation of this species.
But the population is growing very slowly. In addition to these problems, the reason is also that the smaller whales, the minke whales, have occupied the niche. They have been ignored by humans, which has caused them to breed and now eat large swarms of krill before slower, clumsier vomits reach them.
The brain of the blue whale is very small compared to others organs – its weight is only 7 kilograms. At the same time, whales, like dolphins, are smart animals, they are distinguished by high auditory abilities. Scientists believe that they are able to send and receive images through sound, and their brain processes 20 times more information than a human.
Blue whale conservation
Photo: Blue whale from the Red Book
The key measure for the protection of blue whales, taken after they were listed in the Red Book, is a ban on fishing. Due to the fact that they live in the ocean, it is not possible to take more effective protection measures – especially since the waters in which they spend most of their time do not belong to any of the states.
But this is also not particularly necessary. The fact is that in this case, the large size played to the benefit of the blue whales – it is too difficult to get them. This activity requires the use of a large vessel, which makes it almost impossible to organize poaching inconspicuously.
Unlike smaller fish, which are caught in circumvention of prohibitions, the production of vomit after their inclusion in the Red Book has practically ceased. Such incidents have not been recorded for several decades.
Of course, there are other factors that hinder the restoration of the whale population, but the fight against them is too difficult – it is impossible to stop the ongoing pollution of the waters, as well as to drastically reduce the number of ships sailing on it and exposed smooth networks.
Although the latter factor can still be successfully fought: many states have strict standards regarding the size and allowable number of networks. Legislation in some countries also recommends slowing down boats in areas where there are usually a lot of whales.
The blue whale is an amazing creature, and not only because of its size and long life. Researchers are also striving to study the system of their sound signals – in many ways unique and allowing them to communicate over vast distances. Under no circumstances should a species so interesting to study be allowed to disappear.
