What do cetaceans eat - blue whale, fin whale. Brief characteristics of the order Cetaceans
A whale is a sea monster. In the literal sense of the word. After all, this is exactly how the Greek word is translated, from which the name of this amazing animal comes - κῆτος. A lot can be said about marine inhabitants belonging to the order Cetaceans. But it’s worth dwelling on the most interesting facts.
Name
The first step is to answer the question that worries many. And it sounds like this: “Is a whale a fish or a mammal?” The second of the proposed options is correct.
The whale is a large marine mammal that is not related to porpoises or dolphins. Although they are included in the order Cetacea (cetaceans). In general, the situation with names is very interesting. Pilot whales and killer whales, for example, are considered whales. Although, in accordance with the strict official classification, they are dolphins, which few people know.
And it is better to trust a strict classification, since in the old days leviathans were called whales - sea monsters with many heads that could devour the planet. In a word, the name has an interesting story.
Origin
Well, the question “Is a whale a fish or a mammal?” was answered above. Now we can talk about the types of these creatures.
To begin with, it is worth noting that all whales are descendants of land mammals. Moreover, those who belonged to the orders of artiodactyls! This is not fiction, but a scientifically proven fact that was established after molecular genetic examinations. There is even a monophyletic group (clade) that includes whales, hippopotamuses and all artiodactyls. All of them are cetaceans. According to research, whales and hippos descended from the same creature that lived on our planet about 54 million years ago.
Units
So, now - about the types of whales. Or rather, about suborders. The first species is baleen whales. They are the largest of modern mammals. Their physiological feature is a mustache with a filter-like structure.
The second species is toothed whales. Carnivorous, fast creatures. They are superior to toothless whales. Only the sperm whale can compare in size with them. And their feature, as you might have guessed, is the presence of teeth.
And the third species is ancient whales. Those that no longer exist. They belong to a paraphyletic group of animals from which modern species of whales later evolved.
Anatomical features
Now it’s worth considering the description of the whale from a physiological point of view. This animal is a mammal, and it is warm-blooded. Accordingly, each whale breathes with the help of its lungs, and the females feed their calves with milk. And these creatures have hair, albeit reduced.
Because these mammals are exposed to the sun, their skin has protection from ultraviolet rays. True, it is expressed differently in each species. A blue whale, for example, can increase the content of special pigments in its skin that absorb radiation (in simple terms, it “tans”). The sperm whale protects itself from oxygen radicals by triggering a “stress response.” The fin whale practices both methods.
By the way, these creatures maintain their warm-bloodedness due to the presence of a thick fatty layer under the skin. It is this that protects the internal organs of marine animals from hypothermia.
Oxygen absorption process
It is also interesting to talk about how whales breathe. These mammals can stay under water for a minimum of 2 minutes and a maximum of 40. However, there is a record holder, and it is the sperm whale, which is able to stay under water for 1.5 hours.
The external nostrils of these creatures are located at the top of the head. They have special valves that reflexively close the airways when the whale dives into the water. At the moment of surfacing, they open. It is important to know that the airway does not connect to the esophagus. So the whale absorbs air safely, without harm to itself. Even if there is water in his mouth. And by the way, speaking about how whales breathe, it is worth noting that they do it quickly. Speed is facilitated by shortened bronchi and trachea. By the way, their lungs are very powerful. In one breath, the whale renews its air by 90%. And people are only 15%.
It is worth noting that at the moment of surfacing, a column of condensed steam emerges through the nostrils (also called the blowhole). The same fountain that is the calling card of whales. This occurs due to the fact that the whale exhales warm air, which comes into contact with the outside (cold) air. So the fountain is the result of temperature effects. The column of steam varies in height and shape among different whales. The most impressive are the “fountains” of large mammals. They come out of their blowhole with such enormous power that the process is accompanied by a loud trumpet sound. In good weather it can be heard from the shore.
Food
It’s worth saying a few words about what whales eat. The diet of animals is varied. Toothed whales, for example, eat fish, cephalopods (squid, cuttlefish) and in some cases mammals.
Whiskered representatives feed on plankton. They absorb a huge volume of crustaceans, filtering it from the water or using their baleen. These animals can also eat small fish.
The most interesting thing is that in winter whales hardly eat. And for this reason, in the summer they continuously consume food. This approach helps them accumulate a thick layer of fat.
By the way, they need a lot of food. Large whales consume about three tons of food per day.
Bright representative
The blue whale deserves special attention. This is the largest animal that has ever existed on our planet. It reaches 33 meters in length and weighs about 150 tons.
By the way, the blue whale is a representative of the baleen suborder. Feeds on plankton. It has a well-developed filtering apparatus, due to which it filters the absorbed mass inside.
There are three subspecies of this animal. There is a dwarf, southern and northern whale. The last two live in cold circumpolar waters. The dwarf is found in tropical seas.
It is believed that blue whales live for about 110 years. In any case, that was the size of the oldest individual people had ever encountered.
Unfortunately, the blue whale is not a very common marine creature. In the 20th century, uncontrolled hunting began for these animals. By the middle of the last century, only 5 thousand individuals remained throughout the world. People did a terrible thing by exterminating them. Emergency security measures were taken. At the moment, the number of individuals has doubled, but blue whales are still at risk.
Belukha
This is a representative of the toothed whales of the narwhal family. The beluga whale is not very large. Its weight reaches only 2 tons, and its length is 6 meters. Beluga whales have excellent hearing, acute perception of any sounds, and the ability to echolocation. In addition, these are social creatures - there are known cases in which these whales saved a person. They get along well in aquariums, over time they get used to people, and even become attached to workers.
Their diet is varied. Beluga whales eat cod, flounder, herring, clams, algae, shrimp, lamprey, rib jellyfish, pink salmon, gobies, blennies, crayfish and many other sea creatures that are suitable for food.
These creatures, like many others, also suffered due to human cruelty. Whalers easily drove them onto the shallows, and the belugas literally crashed. But at the moment this species is gradually restoring its numbers. Let's just hope people don't ruin anything.
There are dozens of other representatives of cetaceans, and all are special and interesting in their own way. And we hope that every species that we know of will survive. The marine world should not lose any of them, as each of them is a true wonder and natural treasure.
Blue whales are the largest animals on our planet: adults range from 24 to 30 meters in length, while females can exceed the size of males by up to 10 meters. In the XX century. they were almost completely exterminated due to commercial fishing. And only after a general ban on the destruction of whales did their numbers begin to gradually increase.
Top part The whale is mottled blue-gray in color, while the underside is light gray or yellow-white. The yellowish tint of the animal's abdominal part is given by growths of microscopic unicellular seaweeds called diatoms. These plants are common in cold sea waters.
It is officially believed that the largest individual was a female, which was caught by whalers in the last century, 23 m 58 cm long. These animals can weigh up to 200 tons. For comparison, the weight of an African elephant is 7.5 tons. The heart of a blue whale is the size of a car, the beat of which can be heard 3 kilometers away. One of the species is the pygmy blue whale. They are three meters shorter than their larger relatives.
These animals have one incomparable quality: blue whales are the loudest animals on earth. The volume of their call signs reaches 188 decibels, which is significantly higher than the sound of a jet engine - 140 decibels. An animal can hear the song of a relative at a distance exceeding 1.5 thousand km.
In addition to their enormous size, the distinctive features of blue whales are a relatively small dorsal fin, a rounded part of the front of the skull and about 90 longitudinal grooves on the belly, reaching the navel.
Features of communication
Blue whales travel alone for most of their lives, sometimes in groups of 2-3 individuals. Large flocks, which may include 60 animals, have been recorded in places where food accumulates.
But there is one “but” here. The blue whale has the strongest voice of all animals, the low frequencies of which can spread in the deep-sea environment for many hundreds and even thousands of kilometers. Therefore, what may seem to people like “solo” sailing, in reality, is not so. Thanks to the ability for such negotiations, a solitary whale is often in close contact and communication with its relatives.
Nutrition
Whales feed by diving every 10-20 minutes to a depth of about 100 meters. The stomach can hold about one ton of krill at a time. Its requirement for krill is about 4 tons daily during the summer feeding season.
In the mouth there is a so-called “whalebone” of black color. These are horny plates hanging from the upper palate, 300-400 pieces each. from each side. The length of the plates ranges from 50 cm in front to 100 cm in the back. To feed, the animals straighten the “whalebone” in their throats and take in water with krill, sifting it through the horny plates. The water is then released through the baleen and the remaining krill in the mouth is swallowed.
Life cycle
The female usually gives birth to one kitten every two to three years. Currently, this birth rate exceeds the rate of destruction of animals during hunting, which continues to this day.
At birth, the baby whale is the largest newborn animal on earth: it is 8 meters long and weighs about 4 tons. In this case, the female’s pregnancy lasts a year, and usually one baby is born. The cubs grow at a rate of 90 kg per day. Childhood ends at 7-8 months, after the animal reaches 15 m in length and learns to swim independently. Animals reach maturity at 5–10 years.
The growth rate of the blue whale is also amazing and is the highest in the animal kingdom. In just a year and a half, the size of tissues increases several billion times.
Like other cetaceans, blue whales do not have teeth. Therefore, it can be difficult for scientists to determine the age of an animal. It is believed that their average lifespan reaches 50 years, some individuals can live up to ninety, and the oldest animal is considered to die at the age of 110 years.
Extermination of whales
Before the start of active whaling, the population of blue whales exceeded 250 thousand individuals. But in the 20th century. due to merciless hunting they were almost exterminated. Between 1904 and 1967, more than 350 thousand individuals were killed in the southern hemisphere alone. Many animals also died at the hands of Soviet whalers between 1960 and 1970.
The whales suffered especially hard in 1931, which marked the heyday of the fishery. This year, in just one whaling season, more than 29 thousand blue whales were killed. And only in 1967 the situation began to improve, when the world community stood up to protect animals, and whaling was banned.
Population today
Today, blue whales are distributed throughout the world. Their habitat includes all the world's oceans, with the exception of the Arctic Ocean. Blue whales are one of the most rarely seen species of cetaceans. Scientists still haven’t decided how many there are on earth. Their number ranges from 10 to 25 thousand.
One of the many populations of these animals that continues to grow at an encouraging rate is the population of whales that live in the North Pacific Ocean near the US state of California. The number of its representatives reaches 2 thousand.
This species, known as pygmy whales or pygmy whales, lives mainly in the Indian Ocean. Recent research suggests that these animals live in other areas of our planet.
Blue whales prefer to swim in deep ocean waters. In summer they migrate towards the poles, into cooler waters. In winter, the animals swim back towards the equator to warm waters to breed. Due to the fact that the seasons in the northern and southern hemispheres are opposite in time, populations of representatives living in different parts of the planet do not communicate or mix with each other.
Danger to whales
Most biologists have concluded that blue whales are the most endangered of all cetaceans. A serious danger for them is:
- water pollution with chemicals;
- a violation of the natural sound balance, due to which they are unable to find a mate;
- loss of permanent habitat;
- collisions with ships and entanglement in fishing gear.
Climate change could have a significant impact on food supplies, as global warming could shift the pH balance of seawater to acidic levels. This will affect the number of krill that the blue whale feeds on.
Due to climate changes in the frontal zones, the habitats of blue whales, there is a shift further south. In frontal zones, water can rise from the depths, bringing with it gigantic amounts of nutrients. This stimulates the growth of phytoplankton, and also creates conditions for the growth of populations on which the animals feed.
As a result of the migration of frontal zones over a distance of 200-500 km, blue whales are forced to migrate further to feed. Over time, such movements can significantly reduce the body's energy reserves and shorten the feeding seasons. As frontal zones move south, they reduce the areas where species of animals that provide food for blue whales can develop.
After the extinction of dinosaurs, there were not many animals left on Earth that could compete with them in size. On land there are no such creatures at all, but in the seas whales claim this title.
By the way, why are they so big? What do whales eat that causes them to grow to such size? We think that if you didn’t sleep during biology lessons, then you yourself will be able to answer this question perfectly. However, nothing prevents you from slightly refreshing your knowledge in this area.
Oddly enough, these giants do not eat the kind of food that one would think about when looking at the size of their body and monstrous mouth. They practically do not eat fish, if you do not take into account the small things that they come across by chance. So what do whales eat?
About the importance of krill in the diet of sea giants
If, again, you understand even a little about school biology, you may know that the bulk of the ocean’s biomass is phyto- and zooplankton. This is a mixture of tiny organisms that are in no way comparable to the size of the whales themselves. As a rule, these are small crustaceans and their calorie content is very low.
Having figured out what whales eat, it is necessary to talk about the mechanism of this process. At least once, every person has heard about such a concept as whalebone. What kind of mustache is this? After all, no one has ever seen a luxurious mustache grow on his face, like some English gentleman!
What is whalebone used for?
The thing is that this is the name given to special plates in the digestive system of whales. Together they form a kind of giant sieve through which these industrious mammals filter billions of tons of seawater, collecting food for their huge bodies.
By the way, if in the crossword you see something like “what does a whale eat, 5 letters”, then you can safely write the word “krill”, since this is what designates the totality of those organisms that are the food for this
But not all of these mammals give their preference to some crustaceans! We are talking about sperm whales, whose food is sometimes so large that it poses a danger even to the predator itself...
What do sperm whales eat?
This aggressive food is found at depths of over a kilometer. Some sources claim that sperm whales can dive to a depth of almost two kilometers in search of their prey, but authoritative experts believe that the maximum depth of their dives still does not exceed 1.2 km. A whale's food is not always something very small.
What does a whale eat as an infant?
Now about what the cubs eat. If you carefully read our article, you could not help but notice the fact that we have repeatedly mentioned that whales belong to mammals. Simply put, the young of these animals are literally breastfed, growing several tens of centimeters per day. This amazing fact is due to the fact that whale milk is simply amazingly fatty.
So we figured out what whales eat and how it all happens. As you can see, nature is full of all sorts of amazing and unique things!
Scientists classify the blue whale, also called the puking whale, as a baleen whale. The length of this sea animal reaches 33 meters, and its weight sometimes exceeds 150 tons. Currently, he is considered the largest earthly creature. Despite their enormous size, they feed on crustaceans, plankton, krill, and small cephalopods. The giant swims slowly, taking water into its mouth, the volume of which is about 23 cubic meters. The whalebone plates form a remarkably efficient filtering apparatus, through which food is filtered and excess water goes into the ocean. For those who want to know in more detail how the blue whale lives, which are sometimes very diverse and similar to science fiction, it is not so easy to find the necessary materials. The life of this giant has not yet been sufficiently studied, and many data need to be verified.
The blue whale has three subspecies - northern, southern and dwarf. Rare, but still found in India. The blue whale can be considered one of the longest-livers of our planet. On average, its lifespan is about 80 - 90 years, sometimes there are references to the fact that individual specimens were able to live up to 110 years.
Blue whales swim in the ocean in small groups of 2 - 3 individuals. Many adult animals are loners. Sea giants are monogamous; if they form a pair, they stay for life and are never separated. The male always stays close to the female and tries not to swim far from her. In places with an abundance of food, whales gather in large numbers, but even there they swim very scatteredly.
The animal's movements are slow, apparently due to its large body size, it maneuvers poorly and is rather clumsy. Until now, its activity at night and in the evening has been almost not studied; it is assumed that it leads a diurnal lifestyle and moves little at night.
What constitutes the basis of the giant’s diet has been fully studied. This is plankton, crustaceans not exceeding 6 cm in size, from the order of euphausiaceae, which often form huge aggregations - krill. Small fish and small squid are swallowed accidentally during feeding and have no significance for the whale’s nutrition. The sea animal eats plankton along with water, and then closes its huge mouth and squeezes out the remaining water with its tongue through the whalebone. Sometimes it is very difficult for him to “slam it shut”, since, according to measurements, the volume of such water in a 150-ton bottle is 32.6 cubic meters. Often the blue whale does not have enough strength; with its mouth full of food, it is forced to roll over on its side or even on its back, then under the pressure of the sea depths its mouth slams shut. A fully filled stomach of a sea giant can hold up to one and a half tons of food.
Interesting facts about whales include the following information. For about eight months a year, blue whales eat almost nothing; they live on previously accumulated reserves - they use up fat. But in the summer they feed actively, absorb food almost non-stop and quickly restore normal weight. To do this, they swim to the cold, but food-rich Arctic waters of the Southern Hemisphere and feed intensively there for 120 days. In warm tropical latitudes, whales' stomachs are usually empty.
Reproduction
The blue whale has the lowest natural growth rate of all baleen whales. At one time, ketologists (scientists who study cetaceans) believed that the increase in their population could no longer compensate for the decline. In this regard, on February 19, 1986, the International Whale Commission introduced a complete ban on fishing for all species of these marine animals.
Female bleachers give birth to cubs every two years. But recently, due to their small numbers, married couples can form much less frequently. This leads to a decrease in the likelihood of having offspring. The duration of pregnancy is not precisely established, on average it is from 10 to 12 months. Most often, one cub is born, whose body length exceeds 6 meters and weighs 2 - 3 tons. Sometimes there can be twins.
Female blue whales have several embryos at the beginning of pregnancy, the maximum established number of embryos is 7. But in the later stages, most of them resolve, which is typical for many cetaceans. This is an atavism, the legacy of land ancestors who had large offspring.
Bulval females feed milk to their young for the first 7 months. During this time, the “baby” manages to grow up to 16 meters, which is comparable to the size of an adult male sperm whale. Its weight can reach 23 tons. Every day a small whale receives 90 liters of milk, and its weight, on average, increases by 44 kg. The fat content in mother's milk reaches 50%, and the amount of protein and fat together makes up half of the total weight. Therefore, with such nutrition, the cub at the age of one and a half years reaches a mass of 50 tons and grows up to 20 meters in length. Physical maturity in buvals occurs after 15 years.
Short but interesting
In the old days, legends were made about mysterious sea animals and stories were told about them. Many of them were quite fantastic. In those distant times, people believed that it was possible to live in the stomach of this huge creature. In fact, the throat opening of a blue whale is comparable in size to an ordinary saucer. Theoretically, a sperm whale can swallow a person; the size of its throat may well allow this. For many people, the following facts may seem surprising or incredible:
Over the years, the number of blue whales has been gradually decreasing. But many scientists believe that they can still be saved from complete extinction. Famous politicians, actors, and public figures are working on the possibility of preserving these, now rare, marine ones. Thanks to the systematic study of these giants by ketolags, many people learned what it is like, a blue whale, interesting facts about which are replete with incredible data.
You will learn what whales eat.
Whales are marine mammals that are the largest in size, up to 33 meters in length and weighing up to 120 tons. There are baleen whales, which are distinguished by the presence of baleen, to filter plankton from the water, and toothed whales, which hunt fish and squid, and use echolocation.
What do whales eat in the ocean
The diet of the blue whale is practically no different from the diet of other minke whales. It is based on plankton - small crustaceans no more than six centimeters long, from the order Euphausia. These crustaceans form entire clusters - the so-called krill.
whales eat and fish, but it makes up a small part of their diet. Most likely, fish and other small marine animals such as squid and cuttlefish are accidentally ingested by them while eating their main food - krill. It is quite possible that if there are no large concentrations of krill, whales begin to additionally feed on small schooling fish and small crustaceans that do not belong to krill.
In order to eat, the whale opens its huge mouth and takes in water with a mass of krill, fish and small squid. The whale's mouth can stretch, thanks to special stripes on the throat and the movable articulation of the lower jaw bones. After this, the whale closes its mouth and with its large tongue begins to squeeze the water back, filtering it through the whalebone. The plankton lingers and is then swallowed by the whale.
The whale's lower jaw is so huge that it can hold up to 32.6 m³ of water. Because of this, it is sometimes difficult for the whale to close it. Therefore, having collected its food, it often turns on its side or on its back so that its mouth slams shut under its own weight. Because of their enormous size, whales have to eat great amount krill per day, which amounts to several tons.
In the summer, when they gain weight to build up their energy reserves, whales eat up to three and a half tons of food, thereby building up a layer of fat. This fat will act as insulation for them, protecting them from the extremely cold water temperatures at low latitudes. Now you know what whales eat.
On our website you can also find out what they eat , .