A large mustachioed muzzle with expressive eyes, a smooth body, a strong tail and paws - who does not know a seal, who has not seen it at least in a picture or on TV! They are often confused with walruses, but meanwhile they are completely different animals. What are their features and how many types of seals exist?
Who is a seal
Seals belong to the class of mammals that live mainly in the Arctic. These are animals with flippers instead of limbs, it is for this reason that earlier seals (like their walrus relatives) were called pinnipeds. Now this name is not used, considered obsolete.
Among the seals, two families are distinguished - real and eared seals.
Walrus and seal
Many people confuse walruses and seals. It is worth clarifying what is the difference between these animals. So, firstly, there are many types of seals, the walrus is one. It is larger than a seal in size and weight - at least twice. The walrus has large fangs - in other words, tusks with which these animals get food, fight and simply survive. The seal has none.
Walruses do not have ears (this is how the rhyme turned out), but eared seals (you can guess this from their name) have auricles. The whiskers of walruses are thick and wide, while those of seals are thin and narrow. The former have almost no hairline, while the latter have it.
Walruses are peaceful towards each other, they always keep in groups. There are skirmishes between seals (for example, for the territory during the mating season), they often prefer isolation. At the same time, seals are more “talkative”, you can always hear any sounds from them. Walruses are silent.
Earless and eared: what's the difference
As mentioned above, earlier seals were called pinnipeds, but not now: according to some researchers, real and eared seals have different origins. This is their main difference.
The former are the closest relatives of the kunim. That is why they have such an elongated body, like a spindle, which is comfortable to control in the water, and short (in relation to the body) limbs. These seals were in the water for the first time in the North Atlantic Ocean. But their eared counterparts (like walruses) descended from ... bears! A small head, a brownish fur color, tiny ears - all this indicates belonging to a bearish genus. They left land in the Pacific Ocean.
Among other things, these types of seals differ in their flippers. Eared ones are able to step on their hind limbs, walk on the ground with them, while the real ones are deprived of such an opportunity: when they move on land, flippers simply drag behind them. But these animals actively use their rear flippers in the water, swimming with their help. For eared brothers, the means of swimming are the forelimbs, and they use the hind limbs as a kind of "rudder". Another difference between these seals from each other is that the real ones do not have auricles (for this feature they are sometimes also called earless).
The origin of species: a controversial issue
The version about the different origins of seals has its opponents. So, some scientists argue that pinnipeds appeared about fifty million years ago, when neither the mustelid family nor the bear family existed yet. Such researchers are inclined to assume that both true and eared seals nevertheless descended from a common ancestor, belong to the family of pinnipeds and are included in the suborder of canine arctoid predators, which, in addition to them, also included raccoon, canine, mustelid and bear.
Real seal: features
In addition to the already mentioned characteristics of the appearance of a real seal, it must be said about the short neck and the same tail, while the former is inactive. Vibrissa is usually up to ten pieces, they are quite hard. It is vibrissae that help seals navigate in the water: they do not rely on sight, but with the help of whiskers they catch obstacles and successfully overcome them. The front flippers of these animals are even shorter than the rear ones, and are closer to the head. The size and weight of a real seal ranges from one and a half to six and a half meters and from ninety to three and a half thousand kilograms.
Some species of seals do not have hair, but usually it is coarse, not fluffy, of various colors. Seals are characterized seasonal molt. The babies are born with thick, often white and very soft fur, which is replaced after three weeks. Pregnancy in females lasts from two hundred and seventy to three hundred and fifty days, and reproduction (like molting) occurs on ice. The peculiarity of real seals is that mothers stop feeding their cubs with milk quite early, and for several weeks the babies eat only accumulated fat reserves (since they themselves are not yet able to provide themselves with food). In general, real seals eat fish, crustaceans, and molluscs. Some species even prey on penguins.
Representatives of the real seal
Below are the types of seals, names and photos of some of them. Earless seals include 13 genera:
These thirteen genera include, according to various information, from eighteen to twenty-four different species. The most ancient is the Puyila, which lived in the Canadian Arctic.
Eared seal: features
Speaking of appearance eared seals, it should be noted, first of all, that females and males are easy to distinguish by size: males grow up to three and a half meters, females - only up to one. The weight, compared with real seals, in these species is quite small - from one hundred and fifty to a thousand kilograms. The color of the coat, as already mentioned, is brown, the hair itself is hard, coarse. The neck is long, the tail, on the contrary, is short. The hind limbs have claws, while the front ones do not. At the same time, they are quite large - a quarter of the total size of the animal's body.
Eared seals are quite active. They do not like ice, and they prefer to molt and breed on the coast, but they winter in the sea. Pregnancy of females is approximately the same in duration as that of real seals, but they feed babies with milk longer - about four months. After that, the cub is able to take care of its own food. Eared seals, by the way, almost do not eat crustaceans - their diet mainly consists of fish, mollusks, krill. Some species are able to eat the cubs of other seals, penguins, birds.
Types of eared seal
The list of seal species of this type includes fourteen-fifteen (data vary) items that are included in seven genera of two subfamilies. They are (to list a few):
- Fur seals (Northern, South American, subtropical, and so on).
- Sea lions (sea lions, New Zealand, Galapagos and others).
Previously, there was another species of seals - the Japanese sea lion, but now it is considered extinct, since global hunts have been conducted for fur seals and lions since ancient times.
Habitat
True seals love cold and temperate waters. They are mainly found in subpolar latitudes, however, the monk seal prefers the “hotter” area - it is found in the tropics. In addition, it is among the true of all the species of seals in the world that there are freshwater seals that live in Lake Ladoga, Baikal and in Finland.
As for the "eared ones", they live exclusively in the Pacific Ocean - this is if we talk about the Northern Hemisphere. But in the South they can be found in the south South America, as well as Australia - in the Indian Ocean.
Types of seals in Russia
Of the real seals, the fauna of our country boasts nine species (this does not include the endangered monk seal: there are only ten pairs in the Black Sea). Eared seals in Russia are represented by only two species: the northern fur seal and the sea lion (another name is the northern sea lion).
Of all the seals living in our country, you can only catch the Baikal seal, spotted seal (larga), bearded seal and harp seal (all of them are real).
Protected seal species
Many seals, unfortunately, exist on the verge of extinction. Therefore, they are listed in the Red Book and are specially protected animals. Among true seals, there are two such species - these are monk seals and the Caspian seal. At the same time, the first one is generally marked as disappearing - there are no more than five hundred of them in the world today. As for their eared counterparts, the sea lion is now rare, the population of which is no more than seventy thousand.
Although eared and earless seals differ in many ways from each other, they also have similarities, features that are characteristic of these animals.
- Earless seals are clumsy on the ground, but feel great in the water - they are able to reach speeds of up to twenty-four kilometers per hour. Eared seals are mobile both on land and in water; their maximum speed is twenty-seven kilometers per hour.
- They are predators. The fish is not chewed, but swallowed whole. Maximum - they can break into large pieces (they have very sharp teeth).
- They do not have lacrimal glands, but they know how to cry.
- The Baikal seal is a species of seal living in fresh water.
- To find out how old a dead seal is, the circles at the base of the fangs are counted.
- With the help of fat, seals maintain good buoyancy.
- Seal's pulse in the normal state is from fifty to one hundred and twenty beats per minute, and when diving - only four to fifteen beats.
- They have excellent hearing and very poor eyesight.
- Due to the white infant down, newborn seals are called pups. Belek is the subject of hunting for poachers because of its softness and density. Every year, a large number of baby seals die for this reason.
- Capture odors at a distance of several hundred meters.
- They breed once a year.
- To get rid of wool during molting, seals help each other: they scratch their backs.
- Seals have very sensitive sleep.
- The name eared seals was given in the early nineteenth century by the British zoologist John Gray.
- The most numerous species of seal is the crabeater.
- Eared seals waddle along the ground.
- They can "accidentally" swallow stones with food - up to eleven kilograms of stones were found in the stomach of dead animals.
We all are touched when we see a seal - especially if we come to the dolphinarium. But, rejoicing at the meeting with this cute animal, one should not forget that it is we, humans, who are the reason for the decrease in its population. So, it is in our power to do everything to prevent this from happening.
The pinnipeds order is a small group of approximately 30 species. There are three families:
- real seals;
- eared seals;
- walruses.
Predatory animals live mainly in water. They stay on land during certain life periods.
General characteristics
As already mentioned, the representatives of this group are walruses and seals. Let us describe their general characteristics. Pinnipeds are rather large animals with a maximum body weight of 3.5 tons and a body length of up to 6 meters. The elongated rounded body tapers towards the head and tail. The neck is thick and inactive, with the exception of eared seals. Most of the limbs are hidden in the body bag. A thick leathery membrane connects the fingers of the limbs, forming flippers. All this is typical for these mammals (order pinnipeds). In different species of animals, the claws are unequally developed.
They use their limbs only for locomotion. With the help of the hind flippers, animals make oscillatory movements. In this case, the main muscle load falls on back body. The front flippers balance the huge body and act as a rudder. The listed signs of pinnipeds indicate their adaptation to the aquatic environment.
The skin is thick with coarse hair. The subcutaneous fat layer reliably protects against hypothermia. The teeth of this class of animals are designed only for holding and grasping food. The brain box is large, the brain is large. There are no external shells, but they have good hearing. When immersed in the auditory opening narrows due to the muscles. Pinnipeds can make barely audible sounds. The organs of smell are developed satisfactorily. Vision is practically absent. Vibrissae, which are long hairs, serve as the main animals.
While foraging, pinnipeds are able to stay in the water for a long time. The dimensions of the lungs are larger than those of terrestrial predators, and provide a complete exhalation and inhalation of a new portion of air. Lung tissue is elastic, thickened pleura, developed muscles.
Pinnipeds feed on crustaceans, molluscs, seabirds, and fish. Food is obtained only in the depths of the waters.
Walruses and seals prefer to rest on ice floes. Pinnipeds lead a herd life. The largest accumulations of animals are formed during the onset of reproduction and molting. Some prefer others to migrate.
Natural enemies are:
- sea leopards;
- White bears;
- large sharks;
- killer whales.
Pinnipeds come ashore or on ice to mate and reproduce. At three years, puberty occurs. Usually one cub is born once a year. The body of newborns is covered with thick fur, which differs in color and structure from the fur of adults. A few weeks later the fur younger generation is changing. Babies grow up quickly, eating rich mother's milk. After the end of feeding, the cub becomes independent. Pinnipeds live up to 40 years.
walruses
The walrus is one of the largest mammals of the pinniped class.
Representatives of this class can be found in the Chukchi Sea, near the Franz Josef Land archipelago, off the coast of the Novaya Zemlya islands, in the shallow seas of the Arctic Ocean.
Description
Walruses have powerful tusks of 2-4 kg each, which protrude 50 cm above the gum. In females, they are thinner and shorter. main function tusks is the extraction of food by loosening the sandy or muddy bottom surface. Walruses in length can reach up to 4 m, and weigh 1.5 tons. Despite this body weight, these are mobile and agile animals. The entire body of mammals is covered with hard and sparse reddish hairs. Subcutaneous fat up to 10 cm thick reliably protects against hypothermia.
Walruses do not freeze in ice water and they are not afraid of severe frosts. Due to the presence of a subcutaneous air sac, which is connected to the pharynx, they do not drown in water during sound sleep. On the upper lip there are thick, mobile and dense vibrissae (sense organs) located in several rows. By the smell they learn about the approach of danger. They have poor eyesight. External auricles are absent. Nostrils and ear openings close tightly when immersed in water. Fins help animals dive and swim. The rear flippers help push off the surface of the earth and ice.
Lifestyle
On ice floes or coastlines arrange rookeries. In case of danger, they panic, rise from their homes and, crushing each other, go into the water, leaving behind the carcasses of dead animals.
reproduction
Walruses breed from the age of five years once every three or four years. The walrus has one cub. The female feeds him until fangs (tusks) grow. She is a very caring mother and will never leave her cub in danger.
Threats
Uncontrolled walrus fishing led to a significant decrease in the number. Since the fifties of the last century, a ban has been established on their hunting. An exception was made only for the local population (Yakuts, Chukchi), who, under licenses, are allowed to hunt walrus in order to satisfy their personal needs. Some walrus species are included in the Red Book as endangered mammals.
seal family
The elephant seal is the largest representative of pinnipeds among seals and lives in the subantarctic and subarctic seas.
It got its name due to the presence of a leathery bag, which is located in the nose of males. The seal spends most of its life in the water. Males weigh more than three tons and are 6.5 m long. The weight and size of females depend on the genus to which they belong.
Pinnipeds are a commercial species of prey. The skins are used in the manufacture of shoes and clothing. The meat is eaten. The skins of young individuals are used as fur raw materials. The fur of seals is in special demand.
Fur seals, sea lions and walruses are oceanic mammals in the group of pinnipeds (Seals). The connection with water in seals is not as close as in whales. Seals need a mandatory rest on land.
The seals are related but are in different taxonomic families.
- The so-called Earless (true) seals are members of the Canidae family - Phocidae.
- Sea lions and seals are members of the Otariidae family (Sea lions).
- Walruses belong to the Walrus family.
The main difference between earless and eared seals is their ears.
- Sea lions have external ear flaps. These folds of skin are designed to protect the ear from water when the seal swims or dives.
- The "true" seals have no external ears at all. Need get very close to them to see tiny holes on the sides of the seal's smooth head.
Another difference between seal groups is their hind flippers:
In real seals, the hind flippers do not bend and do not tuck forward, but only back. This does not allow them to "walk" on the ground. They move on land with undulating body movements.
Sea lions (fur seals and sea lions) can move on land using their hind legs (flippers).
Third difference:
Fourth difference:
- Sea lions are noisy animals.
- Real seals are much quieter - their vocalizations resemble soft grunts.
There are 18 species of true seals and 16 species of eared seals.
The largest representative of true seals is the southern sea Elephant. Massive male, weighing up to 8500 pounds. (3 855.5 kg). Female elephant seals are much smaller, but still weigh more than a 2,000 lb (907.18 kg) car.
Males measure about 20 feet (6 meters) in length, females are about half as long.
The smallest representative of true (earless) seals is the seal. The seal has an average body length of 5 feet (1.5 m) and a weight of 110 to 150 pounds (50 to 70 kg). Unlike other seals, male and female seals are about the same size.
The ringed seal is the most common seal species in the Arctic, according to a study by the National Oceanic and Atmospheric Administration (NOAA).
Of the 16 species of eared seals, seven are sea lion species.
One of the most known species, according to NOAA, is considered the California sea lion. AT wild nature these animals live along the west coast of North America. They are often seen basking on beaches and marinas.
Males average around 700 pounds (315 kg) and can reach weights in excess of 1,000 pounds (455 kg). Females weigh 240 pounds (110 kg) on average.
Natural environment of seals (seals)
True seals usually live in the cold waters of the Arctic Ocean and off the coast of Antarctica.
Harp (harp seal), ringed seal (akiba), Icelandic hooded seal, bearded seal (beared seal), spotted seal (larga), bearded walrus and lionfish live in the Arctic.
The crabeater, Weddell, leopard seal and Ross seals live in Antarctica.
Fur seals and sea lions live in the northern part Pacific Ocean between Asia and North America, and off the coast of South America, Antarctica, South West Africa and southern Australia. They may spend about two years in the open ocean before returning to their breeding grounds.
Some seals make caves in the snow. Others never leave the ice and poke breathing holes in the ice.
What do seals eat?
Seals primarily hunt fish, but they also eat eels, squids, octopuses, and lobsters.
Sea leopards are able to eat penguins and small seals.
The gray seal is capable of eating up to 10 pounds (4.5 kg) of food a day. He sometimes skips meals for several days in a row, and lives off the energy of stored fat. And often completely stops eating - during the mating season does not eat for several weeks.
All pinnipeds - from true seals (earless) to eared seals (sea lions) and walruses (tusked odobenids) - are carnivores. They are related to dogs, coyotes, foxes, wolves, skunks, otters, and bears.
How do Bellies appear?
When mating season arrives, male seals will make deep guttural sounds to attract the attention of females. The male seal also calls other males to duel with the help of sounds.
Seals are very territorial animals when it comes to mating. They will fight for the right to mate, hit and bite each other. The winner gets the opportunity to mate with 50 females in their area.
Pregnancy of the female lasts about 10 months. When they feel that it is time to give birth, some of them dig nests in the sand, where they have cubs. Other seals lay their babies directly on the iceberg, on the snow.
Belki, so called puppies of seals.
Seals and sea lions only have one pup a year. Baby pups will be nursed on the ground by their mothers until they are covered with waterproof fur. It may take about 1 month.
The females will mate and become pregnant again as soon as her pup is weaned.
Males are not able to mate until they are 8 years old because they need to be big enough and strong enough to win a mating match.
Some other facts about seals
All pinnipeds - seals, sea lions and walruses - are protected under the Marine Mammal Protection Act.
Most seals are not considered endangered, according to the Red List of the International Union for Conservation of Nature (IUCN).
However, there are a few exceptions.
The Caribbean seal was declared extinct in 2008.
- The Galapagos seal and the monk seal are both critically endangered.
- Some local groups, such as the Gray Seals in the Baltic Sea, are also at risk.
- Northern fur seal and hooded seal are also vulnerable.
Northern seals, Baikal seals and Ursula seals are also vulnerable animals. They are trying to breed at the New England Aquarium in Boston.
The crabeater seal, among the seal species, has the most large population in the world. It is estimated that there are up to 75 million individuals.
The elephant seal has what is called "smoker's blood" - it has the same amount of carbon monoxide in its blood as a person who smokes 40 or more cigarettes a day. Scientists believe that this high level of gas in their blood protects them as they dive into the deep levels of the ocean.
Harp seals can stay underwater for up to 15 minutes.
The results of the Weddell seals are even more impressive. Their record for staying underwater is 80 minutes. They only come up for air when they find holes in the layers of ice above the ocean.
Farallones Bay, California National Marine Sanctuary is home to one-fifth of the world's seals. These marine mammals believe they have found a safe haven within the sanctuary.
In the broad sense of the word, seals can be considered all representatives of the order Pinnipeds, but usually this name means animals from the family of true seals. They are closely related to representatives of the eared seal family (fur seals and sea lions) and walruses. Distant relatives of seals are, on the one hand, terrestrial predators, and, on the other, cetaceans, who have completely switched to an aquatic lifestyle. The variety of seals is relatively small, there are about 20 species in total.
Harbor seal (Phoca vitulina).
The appearance of seals clearly indicates their aquatic lifestyle. At the same time, they have not completely lost their connection with the land like cetaceans. All types of seals are quite large animals weighing from 40 kg (for seals) to 2.5 tons (for elephant seals). However, even animals of the same species differ greatly in weight in different times year because they accumulate seasonal fat reserves. The body of the seals is elongated and valky at the same time, the contours of the body are streamlined, the neck is short and thick, the head is relatively small with a flattened skull. The limbs of the seals turned into flat flippers, with the hands and feet being most developed, and the shoulder and femoral girdle shortened.
Common seal on land.
Usually, when moving on land, seals rely on their forelimbs and stomach, while the hind legs drag along the ground. In the water, the front fins act as a rudder and are hardly used for rowing. This differs significantly from the mode of movement of eared seals, which actively use all limbs to move both on land and under water. True seals do not have auricles, and the ear canal is closed by a special muscle during diving. Despite this, seals have good hearing. But the eyes of these animals, on the contrary, are large, but short-sighted. This structure of the organs of vision is characteristic of aquatic mammals. Of all the sense organs, seals have the best developed sense of smell. These animals perfectly capture smells at a distance of 200-500 m! They also have tactile vibrissae (colloquially called whiskers) that help them navigate underwater obstacles. In addition, some species of seals are capable of echolocation, with which they determine the location of prey underwater. True, their echolocating abilities are much less developed than those of dolphins and whales.
The "smiling" face of the leopard seal (Hydrurga leptonyx).
Like most aquatic animals, seals do not have external genitalia, or rather, they are hidden in the folds of the body and are completely invisible from the outside. In addition, seals do not have sexual dimorphism - males and females look the same (the exception is the hooded seal and the elephant seal, the males of which have special "decorations" on the muzzle). The body of seals is covered with hard, short hair, which does not impede their movement in the water column. At the same time, the fur of seals is very thick and is highly valued in the fur trade. The body of seals is also protected from the cold by a thick layer of subcutaneous fat, which takes on the main thermoregulatory function. The color of the body in most species is dark - gray, brown, some species may have a speckled pattern or a contrasting color.
Sea leopard on the shore.
Seals are very widely distributed; in total, the ranges of different species cover the entire Earth. Seals have reached the greatest diversity in the cold latitudes of the Arctic and Antarctic, but the monk seal, for example, lives in the Mediterranean. All species of seals are closely associated with water and live either on the coasts of the seas and oceans, or on vast expanses of pack (perennial) ice.
A crabeater seal (Lobodon carcinophagus) naps on a drifting iceberg shard.
Several species of seals (Baikal, Caspian seals) live in isolation in the inland lakes of the continents (Baikal Island and the Caspian Sea, respectively). True seals roam over short distances, they are not characterized by long migrations like fur seals, for example. Most often, seals form group concentrations - rookeries - on the shore or on an ice floe. Unlike other species of pinnipeds (fur seals, sea lions, walruses), true seals do not form dense and numerous herds. They also have a much weaker herd instinct: for example, seals feed and rest independently of each other and only monitor the behavior of their brethren in case of danger. Between themselves, these animals do not quarrel (with the exception of the mating season), there have been cases when, during the molt, seals scratched each other's backs in a friendly way, helping to get rid of old wool.
Seals bask on the coastal cliff.
Seals on the shore are clumsy and helpless: they usually lie close to the water, from time to time diving into the polynya for prey. In case of danger, they rush to dive, while moving with visible effort, but once in the water they swim quickly and easily. Seals are able to dive to great depths and stay under water for a long time. The record holder in this is the Weddell seal, which can stay under water for 16 minutes, while diving to a depth of 500 m!
Seals feed on a variety of aquatic animals - fish, mollusks, large crustaceans. Different types they prefer to hunt for different prey, for example, the leopard seal - for penguins, the crabeater seal - for crustaceans, etc.
The leopard seal caught the penguin.
All species of seals breed once a year. During the rut, skirmishes arise between males. Male hooded seals have an outgrowth on their nose, which inflates when the animal is excited. Puffing out their noses and roaring loudly, Ukrainians fight for the attention of females. Elephant seals have a fleshy nose and look like a short trunk; angry males during clashes not only roar and puff out their noses, but also bite each other, causing serious wounds. Pregnancy of females lasts almost a year. Seals always give birth to only one, but large and developed cub.
In many seals, the pups are covered with children's white fur, which is completely different from the coloration of adults, so they are called pups.
Although pups at first cannot accompany their mother in the water, they are well adapted to low temperatures and the first time is constantly spent on ice. Babies grow fast thanks to extremely high-fat milk rich in protein.
