What kind of animals are dolphins? Why do people have long been especially fond of them? And dolphins are very friendly to people, showing great interest. There are many cases of salvation of drowning by these creatures. They are very amenable to training, as they are very reasonable and have incredible quick wits. About what animals dolphins belong to will be described in the article. And also about where they live, how they breathe, and their other features.
Dolphins are not fish
Dolphins are not fish. Although outwardly they are very similar to them in their form. Dolphin is a class of mammalian animals. They are part of a cetacean squad, a toothed whale suborder. And also they are divided into sea and river. Sea dolphins are called dolphins, and river dolphins are called dolphins, or freshwater.
The first swim in open seas, only occasionally swimming in the mouth of large rivers. The second are much less common, mostly they are found in fresh inland waters. But occasionally penetrate into saline estuaries (flooded estuaries) and coastal marine areas. The most common sea dolphins are common dolphins and bottlenose dolphins. We will consider them in more detail later.
general description
Dolphin is a marine animal whose body has an oblong shape, which allows it to literally glide through the water at a speed of about 50 kilometers per hour. This is also favored by oily skin secretions. The length of individuals ranges from 2 to 4.5 meters, and weight - from 150 to 300 kilograms.
In most cases, there is a fin on the back, mainly in the form of a sickle. The mouth resembles a beak, the number of teeth can reach the number 272, which is a record for mammals. The teeth look like sharp spikes, which is ideal for holding slippery fish.
Dolphins have small eyes and poor eyesight. The nostrils as such are absent; instead of them, on the crown of the head there is a drawbar. Dolphins stay in water for a long time, but periodically float to the surface to capture air.
How do dolphins breathe and sleep?
Dolphins are a group of animals that have no ears. However, they have a rumor, although not in the usual sense. Sounds are perceived by dolphins through the inner ear and sinuses in the forehead, acting as resonators. Dolphins are animals that own echolocation. They can, without the slightest error, determine where the object is and what its dimensions are, by the sound it reflects. And they calculate the distance by the wavelength.
A distinctive feature of dolphins is the fact that they are never completely immersed in sleep. They only rest, freezing among the water column, and from time to time float to the surface to breathe. Each of the hemispheres of the brain, dolphins turn off in turn, so they are always half awake.
Communication and food
Dolphins are socialized animals, they gather in flocks, which can number from ten to several thousand individuals. So it is easier for them to defend themselves from attacks by enemies. Relations in packs are characterized by peace and tranquility, lack of competition.
Dolphins “talk” with the help of many different sounds that can be described as whistling, barking, twittering, clicking. They are in the low frequency range up to ultrasound. There is a combination of them with each other, developing into “words” and “phrases”.
Dolphin diet consists of "fish dishes", among which stand out anchovies and sardines. An interesting way of hunting is when a flock surrounds a fish school and, making a special kind of sounds, helps it to stray into a dense formation. As a result, its main part becomes the prey of dolphins. A number of facts are known, according to which dolphins helped fishermen in this way.
Reproduction and cubs
Dolphins are animals that do not have a pronounced mating season. As a rule, the leader of the pack mates with females. Pregnancy lasts about 18 weeks and is a difficult time, during which the female is slow, moves slowly and often becomes someone’s prey. One cub about half a meter long appears approximately once every two years. He is fully capable of moving after his mother.
Up to a year and a half, the young suck mother’s milk, they do this often and grow rapidly. After that, they switch to a fish diet. Only female representatives of the pack educate and teach little dolphins.
Common dolphins and bottlenose dolphins
Let's take a closer look at the most common dolphins. Ordinary - dolphins (the photo of the animal is given above), which are found in almost all the seas of the Northern Hemisphere: both on the coast and in open waters, it happens that they enter rivers. They have a huge number of small teeth that are conical and bent inward. The muzzle is separated from the somewhat convex forehead by a furrow, its length is moderate. Above the body and fins can have such shades as gray, greenish and black, belly - white.
The skin is extraordinarily smooth and shiny. Ordinary dolphins can be up to two meters long, and the fin located on the back is close to 80 centimeters. The fins adjacent to the chest are about 20 centimeters wide, and about 60 in length.
Bottlenose dolphins are dolphins (a photo of an animal demonstrates its appearance), which are the most famous and popular variety. As a rule, when dolphins are mentioned, an association arises precisely with them. They are most often trained and shot in the movies. Bottlenose dolphins live in the north of the Atlantic, sometimes entering the Baltic. They are much less common than ordinary dolphins, and much larger than them, in length they can reach from 3.5 to 4.5 meters.
Interesting about dolphins
You can hear a lot of interesting things about dolphins, here are some of these facts:
- In culture, the image of a dolphin has been present since ancient times. They were depicted on coins of Ancient Greece in the 5th century BC, on ceramic products. In Africa, a stone is found that is more than two thousand years old, with animals painted on it, similar to dolphins.
- The sharp teeth of a dolphin serve him not for chewing food, but only for its capture and retention. Since it is swallowed whole.
- From rubbing against water, the skin of a dolphin is subject to rapid abrasion. To offset this drawback, nature provided for the presence of a large supply of regenerating cells. Dolphin molts several times during the day.
- Dolphins are on friendly terms with sharks. Often they arrange a joint hunt.
- There were so-called fighting dolphins. The military structures of the USSR and the USA trained individuals living in the ocean to perform certain combat missions.
- One of the methods of psychotherapy is dolphin therapy, based on the communication of these amazing animals and humans. With its help, children are treated with autism, hyperactivity, cerebral palsy.
- In our time, hunting for dolphins is prohibited, but despite this, their numbers are constantly declining, and some species are on the verge of extinction. Many water parks are breeding endangered species.