The author of many books about animals, the famous Soviet naturalist Igor Akimushkin, having studied the incredible abilities of octopuses, called them "primates of the sea." Octopuses, like squids, cuttlefish, nautiluses belong to the class of cephalopods, inhabiting the warm seas and oceans of the planet. Science today has more than 800 species of these amazing animals, and together with fossil species there are about 10 thousand. We will plunge into the enchanting world of the ocean, and find out the most interesting facts about cephalopods, their lifestyle, body structure and habits.
1
Specific name
Because of the peculiar appearance of the mollusks, they are called cephalopods (Cephalopoda). As a result of evolution, part of the leg moved to the head of the animals, forming tentacles. Cuttlefish and squid have 10, but octopuses have 8.
In nature, there are two main genera. The first is biconjug, which includes cuttlefish, squid and octopus. The second is the nautiloids, represented by the nautiluses and the species Allonautilus.
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Mental organization
All members of the class have a developed brain and are quick-witted. In octopuses, zoologists note the highest mental organization.
They best absorb information from the outside world and use its octopuses. They easily establish a connection between objects and by analyzing, they foresee the course of events.
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Rudiment
There is another feature in the structure of their bodies. Due to the mobile lifestyle, the shell transformed into small plates that hid under the mantle.
By the way, there is a fascinating article about the most unusual sea creatures that look like fantastic aliens on our site most-beauty.ru.
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Speed record holders
At the end of the tentacles, a peculiar funnel formed in the cephalopods. Together with the mantle, these holes act as an engine. Water is pushed with great force through these funnels, helping the animal develop a high speed.
Movement is jerky. Some octopuses can accelerate in water up to 70 km / h, and squids, with the help of such a "jet engine", can fly, pushing themselves out of the water.
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Dimensions
The largest octopus is an animal named after the German zoologist Doflein. The Guinness Book of Records reports that the length of an adult is 9.2 m, while the record holder weighs 272 kg.
The tentacles of the largest squid were found in the stomach of a caught whale. After examining the organ, scientists came to the conclusion that its length should reach about 18 meters.
Giant cuttlefish grows up to two meters in length.
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The oldest
The remains of nautiluses are found in the layers of the Eocene and Lower Oligocene. They appeared on the planet about 50 million years ago and are considered one of the most ancient creatures of the terrestrial fauna.
Over their long history, they have not changed much. They have preserved a shell, with the help of which they move in the water column, and also protect themselves from natural enemies.
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Protection
All representatives of cephalopods protect themselves from predators by throwing a cloud of ink into the water. For octopuses, such a cloud takes the form of the octopus itself, disorienting the attacker, and at this time he manages to slip away.
Such protective agents not only reduce visibility, but also mask odors. Despite this, cephalopods themselves are also predators.
8
Autonomy
There is another remedy. When the predator has already captured the cephalopod mollusk, it can discard the tentacles, which also disorients the enemy.
The cut off part of the body for a long time retains the ability to wriggle in the water, which scares the attacker. Then the discarded part of the body grows again.
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Suction Cup Multifunctionality
Suction cups on tentacles perform several functions at once. These are peculiar taste buds with the help of which marine inhabitants determine the edibility or inedibility of an object.
With the help of suction cups, they move along the bottom, and can also lift weights. One tentacle tentacle can lift a weight of 100-130 gr.
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Blue Blood Animals
Almost all representatives of the genus Cephalopoda contain a large amount of copper in the blood, which is why the blood turns blue. But the editors of most-beauty.ru found that in fact it is colorless, and acquires a blue hue only when interacting with oxygen.
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Three hearts
Amazing creatures have three hearts. One pumps blood throughout the animal’s body, while the other two pump blue blood through the gills.
Cephalopods are the only mollusks that have a closed circulatory system.
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Nautilus shell
Cuttlefish, squid and octopus have a shell inside, but nautilus shells also have an outer shell. It is divided into several segments.
In one, during the danger, the animal itself hides, but in the second compartment water and gas are pumped. By adjusting the density, the nautilus can sink to the bottom, or rise in the water.
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Vision
Cephalopods will give odds to any inhabitant of the seas and oceans in visual acuity. The structure of the eye is similar to the human organ of vision, but the cornea is not continuous, but has a small hole.
In addition, their pupil has a rectangular shape, which allows to increase the viewing angle.
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Breeding
Almost all members of the cephalopod family mate only once in a lifetime. The male with a tentacle takes spermatophores from a special reservoir, and places them in the female’s cavity sacs.
Argonauts mate originally. Its genital organ, the hectocotyl, simply disconnects from the body of the male and independently fertilizes the female. After this, the special tentacles of the male grows again.
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Offspring
The development of the egg in the nautilus occurs within 6 months, but the baby who has appeared already has a shell, is completely ready for independent life.
Octopus babies begin to live on their own, as the female dies immediately after the offspring.
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Ability to change colors and sizes
The process of mimicry is regulated by the nervous system of animals. Cells are able to change color and size, helping cephalopods adapt to their environment and take on various forms. Some species may be transparent.
A boneless skeleton helps cephalopods easily penetrate holes much smaller than themselves. Mimicry and the ability to change forms often save animals from dangerous predators.
By the way, on our site most-beauty.ru there is an interesting article about 15 incredibly beautiful transparent animals, the existence of which is hard to believe.
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Diet
All cephalopods are excellent hunters. The only ones who do not hunt are nautilus. The structure of the body does not allow them to move quickly. They feed on carrion, which they find on the seabed, but can catch small fish or crustaceans.
But their digestive system is so developed that it makes it easy to digest even strong crustacean shells.
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Natural material
Liquid is extracted from the ink glands of cuttlefish and squid, from which a watercolor paint is created - sepia. But the Chinese on the basis of such ink make mascara.
But the nautilus shells are covered with mother-of-pearl from the inside, which is why the animals were caught. In the Middle Ages, bowls were made from helical shells, from which nobility drank wine at feasts and dinners.
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Baseless allegations
Animals with tentacles do not pose a great danger to humans, and the image of a ruthless sea monster arose from the filing of some writers, and then filmmakers.
The ancient sailors, unable to explain the phenomena of nature and the death of ships, connected them with sea monsters, which with huge tentacles pulled to the bottom of the vessel along with the crews.
Icelandic sailors talked about a huge kraken, a mythical creature attacking ships in the northern seas.
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Danger to humans
But in all the variety of benevolent creatures, there are those that pose a real threat to humans. There are animals in which the glands contain poison.
In history, cases have been recorded when large individuals attacked a person, but scientists attribute this to self-defense rather than aggressive disposition.
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In popular culture
Victor Hugo described the image of a terrible marine inhabitant in his novel "Workers of the Sea." At the beginning of the 19th century, a Japanese artist created an erotic engraving "The Dream of a Fisherman's Wife", on which a woman stands surrounded by two octopuses.
In the Soviet animation, the funny cartoon by Eduard Uspensky “Octopuses” is known. The Detroit Red Wings hockey club before the start of the Stanley Cup playoff series throws an octopus onto the ice. Fans believe that eight tentacles symbolize eight victories that need to be gained in order to raise the coveted trophy overhead.
The famous rock band Nautilus Pompilius is named after the beautiful clam Nautilus Pompilius, which is also called the Ordinary Boat.
Summary
We hope that we have answered all your questions, and our dear reader has learned a lot about the intelligent inhabitants of the seas and oceans. Now to the test questions: in which animals instead of the legs of the tentacle and who does not belong to the cephalopods, an exact and correct answer will be given.