How many children did the octopus have? Octopus - octopus: description with photos, pictures and videos, structure of tentacles, is it true that an octopus has a square pupil and can change color. How long do octopuses live?

Octopuses are the most famous of the cephalopods, but nevertheless hide many secrets of their biology. There are 200 species of octopuses in the world, classified as a separate order. Their closest relatives are squids and cuttlefish, and their distant relatives are all gastropods and bivalves.

Giant octopus (Octopus dofleini).

The appearance of the octopus is a little disconcerting. Everything about this animal is not obvious - it is not clear where the head is, where the limbs are, where the mouth is, where the eyes are. It's actually simple. The sac-like body of an octopus is called the mantle; on the front side it is fused with a large head, on top surface which contains bulging eyes. The mouth of an octopus is tiny and surrounded by chitinous jaws - a beak. Octopuses need their beak to grind food, since they cannot swallow prey whole. In addition, they have a special grater in their throat that grinds pieces of food into pulp. The mouth is surrounded by tentacles, the number of which is always 8. The tentacles of an octopus are long and muscular, their lower surface is studded with suckers of different sizes. The tentacles are connected by a small membrane - the umbrella. The 20 species of fin octopuses have small fins on the sides of their bodies that are used more as rudders than motors.

Fin-finned octopuses due to wing-like fins resembling ears in English language called Dumbo octopuses.

If you look closely, you can see a hole or a short tube under the eyes - this is a siphon. The siphon leads into the mantle cavity, into which the octopus draws water. By contracting the muscles of the mantle, he forcefully squeezes water out of the mantle cavity, thereby creating a jet stream that pushes his body forward. It just turns out that the octopus is swimming backwards.

The octopus' siphon is visible just below the eye.

Octopuses have a rather complex structure internal organs. Yes, their circulatory system almost closed and tiny arterial vessels almost connect with venous ones. These animals have three hearts: one large (three-chambered) and two small ones - gills. The gill hearts push blood to the main heart, which directs blood flow to the rest of the body. Octopuses' blood is...blue! The blue color is due to the presence of a special respiratory pigment - hemocyanin, which replaces hemoglobin in octopuses. The gills themselves are located in the mantle cavity; they serve not only for respiration, but also for the release of decay products (together with the kidney sacs). The metabolism of octopuses is unusual because they excrete nitrogenous compounds not in the form of urea, but in the form of ammonium, which gives the muscles a specific smell. In addition, octopuses have a special ink sac in which dye is stored for protection.

The octopus' funnel-shaped suckers use the suction force of a vacuum.

Octopuses are the most intelligent of all invertebrate animals. Their brain is surrounded by special cartilage, which surprisingly resembles the skull of vertebrates. Octopuses have well-developed sense organs. The eyes have reached the highest perfection: they are not only very large (they occupy most of the head), but also complex in structure. The structure of the octopus's eye is fundamentally no different from the human eye! Octopuses see separately with each eye, but when they want to look at something more closely, they bring their eyes together and focus them on the object, that is, they also have the rudiments of binocular vision. The viewing angle of the bulging eyes approaches 360°. In addition, light-sensitive cells are scattered in the skin of octopuses, which make it possible to determine general direction Sveta. Octopuses have taste buds... on their arms, or rather on their suction cups. Octopuses do not have hearing organs, but they are able to detect infrasounds.

Octopuses have rectangular pupils.

Octopuses are often colored brown, red, or yellowish, but they can change color no worse than chameleons. The change of color is carried out according to the same principle as in reptiles: in the skin of octopuses there are chromatophore cells containing pigments, they can stretch and contract in a matter of seconds. Cells contain only red, brown and yellow pigments, alternate stretching and contraction of cells different color creates a wide variety of patterns and shades. In addition, under the layer of chromatophores there are special irridiocyst cells. They contain plates that rotate, change the direction of light and reflect it. As a result of the refraction of rays in irridiocysts, the skin can turn green, blue and Blue colour. Just like chameleons, the change in color of octopuses is directly related to the color of the environment, the well-being and mood of the animal. A frightened octopus turns pale, while an angry one turns red and even black. It is interesting that the change in color directly depends on visual signals: a blinded octopus loses the ability to change color, a blinded octopus in one eye changes color only on the “sighted” side of the body, tactile signals from the tentacles also play a certain role, they also affect skin color.

An "angry" blue reef octopus (Amphioctopus marginatus) with an unusual coloration. When calm, these octopuses are brown with blue suckers.

The largest giant octopus reaches a length of 3 m and weighs 50 kg; most species are medium and small in size (0.2-1 m in length). A special exception is the male Argonaut octopus, which is much smaller than the females of its species and barely reaches a length of 1 cm!

The habitat of various species of octopuses covers almost the entire world, only in the polar regions you will not find them, but still they penetrate further north than other cephalopods. Most often, octopuses are found in warm seas in shallow waters and among coral reefs at a depth of up to 150 m. Deep-sea species can penetrate to depths of up to 5000 m. Shallow-water species usually lead a sedentary bottom lifestyle, most of the time they hide in reef shelters, between rocks, under stones and come out only to hunting. But among octopuses there are also pelagic species, that is, those that constantly move in the water column far from the shores. Most pelagic species are deep-sea. Octopuses live alone and are very attached to their area. These animals are active in the dark, they sleep with their eyes open (they only constrict their pupils), and octopuses turn yellow in their sleep.

The same blue reef octopus in a calm state. These octopuses love to settle in the shells of bivalve mollusks.

There is an opinion that octopuses are aggressive and dangerous to humans, but this is nothing more than prejudice. In reality, only the most dangerous scuba divers react to a threat. large species and only during the breeding season. Otherwise, octopuses are cowardly and cautious. They prefer not to get involved even with an enemy of equal size, and they all hide from large ones possible ways. These animals have many methods of defense. Firstly, octopuses can swim quickly. They usually move along the bottom on half-bent tentacles (as if crawling) or swim slowly, but when frightened they can make jerks at speeds of up to 15 km/h. A fleeing octopus tries to hide in a shelter. Since octopuses have no bones, their body has amazing plasticity and is able to squeeze into a very narrow crack. Moreover, octopuses build shelters with their own hands, surrounding crevices with stones, shells and other debris, behind which they hide as if behind a fortress wall.

Octopus in shelter surrounded itself building material- shell shells.

Secondly, octopuses change color, camouflaging themselves with the surrounding landscape. They do this even in a calm environment (“just in case”), and skillfully imitate any surface: stone, sand, broken shells, corals. The octopus imitator from Indonesian waters imitates not only the color, but also the shape of 24 species of marine organisms (sea snakes, stingrays, brittle stars, jellyfish, flounder, etc.), and the octopus always imitates the species that the predator that attacks it is afraid of .

A mimic octopus (Thaumoctopus mimicus) masquerading as a lobster.

On soft soils, octopuses bury themselves in the sand, from where only a pair of inquisitive eyes stick out. But all these methods of protection are nothing compared to the know-how of octopuses - the “ink bomb”. They resort to this method of defense only when very frightened. A swimming octopus releases a dark-colored liquid from its sac, which disorients the enemy and more... The liquid affects nerve receptors, for example, it deprives the sense of smell for a while predatory moray eels, there is a known case when liquid got into the eyes of a scuba diver and changed his color perception; for several minutes the person saw everything in yellow. The musk octopus's ink also smells musky. Moreover, often the released liquid does not dissolve in water instantly, but for several seconds retains the shape... of the octopus itself! Here's a decoy and chemical weapon the octopus slips it to its pursuers.

And this is an octopus imitator, but already pretending to be a stingray.

Finally, if all the tricks do not help, the octopuses can engage in open battle with the enemy. They show an unbending will to live and resist to the last: they bite, try to gnaw through nets, try to mimic until their last breath (there is a known case when an octopus, pulled out of the water, reproduced on its body... lines from the newspaper on which it was lying!), grabbed by the one tentacle, the octopuses sacrifice it to the enemy and discard part of the arm. Some species of octopuses are poisonous; their venom is not fatal to humans, but causes swelling, dizziness, and weakness. The exception is blue-ringed octopuses; their nerve venom is fatal and causes cardiac and respiratory arrest. Fortunately, these Australian octopuses are small and secretive, so accidents involving them are rare.

Large blue-ringed octopus (Hapalochlaena lunulata).

All octopuses are active predators. They feed on crabs, lobsters, bottom mollusks, and fish. Octopuses catch moving prey with their tentacles and immobilize them with poison, and the suction force of the tentacles is great, because only one sucker of a large octopus develops a force of 100 g. They gnaw the shells of sedentary mollusks with their beak and grind them with a grater; the poison also slightly softens the shells of crabs.

Swimming giant octopus moves back side body forward and head back.

A clutch of spiny octopus (Abdopus aculeatus) is visible between the tentacles of a caring mother.

Female octopuses are exemplary mothers. They entwine the masonry with their hands and carefully lull it to sleep, blow away the smallest debris with water from their siphon, during the entire incubation period (1-4 months) they do not eat anything and eventually die from exhaustion (sometimes their mouth even becomes overgrown). Males also die after mating. Octopus larvae are born with an ink sac and can create an ink curtain from the first minutes of life. In addition, small octopuses sometimes decorate their tentacles with stinging cells. poisonous jellyfish, which replace their own poison. Octopuses grow quickly, small species live only 1-2 years, large ones - up to 4 years.

A giant octopus displays a membrane (umbrella) between its outstretched tentacles.

In nature, octopuses have many enemies; they feed on them. large fish, seals, sea ​​lions and seals, seabirds. Large octopuses can dine on small relatives, so they hide from each other no less than from other animals. People have been hunting octopuses for a long time. Most of these animals are caught in the Mediterranean Sea and off the coast of Japan. In Eastern and Mediterranean cuisine, there are many dishes with octopus meat. When catching octopuses, they use their habit of hiding in secluded places; to do this, broken jugs and pots are lowered to the bottom, into which the octopuses crawl, then they are raised to the surface along with the false house.

The common octopus (Octopus vulgaris) Paul “draws lots” - opens the feeder.

It is difficult to keep octopuses at home, but in public aquariums they are welcome guests. It is interesting to watch these animals; they can develop elementary conditioned reflexes; octopuses solve some problems no worse than rats. For example, octopuses perfectly distinguish between all kinds of geometric figures, and they recognize not only triangles, circles, squares, but can also distinguish a lying rectangle from a standing one. When well cared for, they recognize the person caring for them and greet him, crawling out of the shelter. The most famous pet was the common octopus Paul from the Center Oceanarium sea ​​life» in Oberhausen (Germany). The octopus became famous for accurately predicting the victory of the German football team during the World Cup in 2010. Of the two feeders offered, the octopus always opened the feeder with the symbols of the winning team. The mechanism of the “prophecies” remained unknown; Paul died in 2010 at the age of about 2 years, which corresponds to the natural life expectancy.

When we are told about the class of cephalopods, octopuses are the first to come to mind. Typical representatives live at the bottom of the water, but some of them inhabit the high layers of seas and oceans. This inhabitant big waters always surprised ordinary people, since it has a ball-shaped body, long tentacles, a specific nose and great intelligence.

Interesting!

Many people were interested in the question of how many hearts an octopus has. A small number of animals have three “engines of life”. Science includes in the squad all these cephalopods known species, from the smallest to colossal-sized individuals.

The structure of the octopus

This animal has the ability to modify the shape of its body, since there are no bones in the structure of its body. Some cephalopods can disguise themselves as flounder if necessary. These flexible creatures are able to settle in a very narrow and cramped place, the size of which is several times smaller than the body of the mollusk. They are able to hear a variety of sounds.

On a note!

Each octopus sucker can hold up to 100 grams of weight. To maintain an object on a tentacle, a marine animal must exert sufficient muscle force.

How do octopus hearts work?

The heart is a muscle, contracting at a certain speed in order to conduct blood throughout the cells of the body. The main inconvenience in the structure of the mollusk is that its gills are endowed with too much resistance. Nature found a reasonable solution and endowed the cephalopod with three heart muscles to increase the utility coefficient.

The main heart has a large volume, and the other two, located near the gills, are somewhat smaller. All three muscles beat synchronously, and the frequency of the beat depends on the temperature of the water. Cold reduces the number of beats per minute. Blood is blue because it contains the enzyme hemocyanin with copper impurities.

Color and size of octopuses

The cephalopod has the ability to change the color of its body due to different pigments in its skin, adapting to its environment. Under the influence of the animal’s nervous system and sensitivity, the spots can narrow or, on the contrary, stretch. Each emotion of a cephalopod is determined by a corresponding color: white – fear, red – anger, brown – calm state.

In nature, you can find centimeter or four-meter individuals. The weight of the most major representatives can reach 50 kg. There are rumors of incredibly large octopuses that heavier than a man three times. The mollusk lives on average about two and a half years.

Octopus behavior and habitat

The mollusk prefers to live in the waters tropical climate. Depending on the species, some like shallow water, while others are more comfortable going to greater depths. The octopus builds a home on rocky shores or inside natural caves. Since it has no bones, even a small gap can become suitable for resting during the day and hiding from predators. If there are no rocks around the animal, it is able to make its own home from materials on the ocean floor. In addition, the mollusk can dig a deep hole in the ground, which it will then arrange to suit its taste.

To move across the surface, the octopus uses suction cups on its tentacles. It can swim by drawing water into the gill cavity and then pushing it back with great effort. If we compare the speed of its movement with fish, then we can say that the octopus is a very slow creature. At the sight of danger, the octopus throws streams of dark liquid in the direction of its pursuers, which are formed under the influence of special glands. This distracting cloud remains a dense spot for a long time and stops the creatures that disturbed the peace of the octopus.

The cephalopod goes hunting only at night. Its diet includes small shellfish, various crayfish and a variety of fish. The octopus will feast on every inhabitant of the depths if he can handle it. Using a camouflage technique, the cunning octopus waits for prey at the bottom sea ​​depth, and when she gets close, she attacks. The octopus clasps its prey with all eight “arms”. Having bitten its prey with its beak and injected strong poison into it, the octopus dooms its dinner to certain death. The internal structure of the octopus allows it to easily grind paralyzed food.

Interesting!

Autotomy is a protective device that some types of creatures are endowed with. If an enemy grabs the octopus's "arm", there is a high probability that along with the rupture of the muscles at the base of the tentacle, the tentacle itself will also come off . Such a limb for a while continues to move and distract the attention of the predator.

The minds of animals and their methods of reproduction

Nests where the female lays spherical eggs 10-20 pieces each, located in dug holes, surrounded by stones and shells. The mother monitors the offspring very carefully, removing unnecessary objects and dirt with her tentacles. The female loves her cubs so much that she cannot be separated from them for even a minute and often dies of hunger after the small cephalopods have hatched from the eggs. This shows that the octopus's heart is akin to that of a good human.

Features and habitat of the octopus

Octopuses They are benthic animals, a species of cephalopods, found exclusively in the water column, most often at great depths.

Pictured is an octopus may appear shapeless due to the rather soft short body of an irregular oval shape and the complete absence of bones in the body.

The animal's mouth, equipped with two powerful jaws, is located at the base of the tentacles, the anus is hidden under the mantle, which in appearance looks like a dense wavy leather bag.

The process of chewing food occurs in the so-called “grater” (radula), located in the throat.

The photo shows the mouth of an octopus

Eight tentacles extend from the animal’s head, which are connected to each other by a membrane. Each tentacle has several rows of suckers.

Adults big octopuses can have a total of about 2000 suckers on all “arms”. In addition to the quantity of suction cups, they are also notable for their high holding force - about 100 g for each.

Moreover, this is achieved not by suction, as in the human invention of the same name, but exclusively by the muscular effort of the mollusk itself.

In the photo there are octopus suckers

The cardiac system is also interesting, since octopus has three hearts: the main one ensures the passage of blue blood throughout the body, the minor ones push the blood through the gills.

Some types sea ​​octopuses They are extremely poisonous, their bite can be fatal both for other representatives of the animal world and for humans.

Another notable feature is the ability to change the shape of the body (due to the lack of bones).

For example, taking the form of a flounder, octopus hiding on seabed , using this both for hunting and for camouflage.

Also, the softness of the body allows giant octopus squeeze through small holes (several centimeters in diameter) and stay in a confined space whose volume is 1/4 of the size of the animal, without experiencing any inconvenience.

The octopus's brain is highly developed, donut-shaped and located around the esophagus. The eyes resemble human ones in that they have a retina, however, the octopus's retina is directed outward and the pupil is rectangular.

Octopus tentacles extremely sensitive due to the huge number of located on them taste buds.

An adult can grow up to 4 meters in length, while representatives of the smallest species (Argonauto argo) in mature age They grow only up to 1 centimeter.

In the photo there is an octopus Argonaut

Accordingly, depending on the type and length, the weight also varies - the largest representatives can weigh 50 kilograms.

Almost any octopus can change color, adapting to the environment and situation, since the skin of the mollusk contains cells with different pigmentation, which shrink and stretch at the command of the central nervous system. The standard color is brown, when scared - white, when angry - red.

Octopuses have a fairly wide distribution - they are found in all tropical and subtropical seas and oceans, from relatively shallow waters to a depth of 150 meters. For permanent habitats, they choose rocky areas; they love crevices and gorges.

Due to its wide distribution, octopuses are eaten by residents of many countries.

For example, in Japan, this strange animal is a common product that is used in the preparation of many dishes and is also eaten live.

Salted octopus meat is widespread in Russia. Also, for everyday purposes, namely for drawing, mollusk ink is used, which is extremely durable and has an unusual brown tint.

Character and lifestyle of the octopus

Octopuses prefer to stay close to the seabed among algae and rocks. Juveniles like to hide in empty shells.

IN daytime mollusks are less active, due to which they are considered to be nocturnal animals.

The octopus can easily move on hard surfaces with almost any slope thanks to its strong tentacles.

Often, octopuses use a method of swimming in which the tentacles are not used - they draw water into the cavity behind the gills and move, pushing it out with force.

When moving in this way, the tentacles stretch behind the octopus. But, How many no matter what at the octopus swimming methods, they all share a common drawback - the animal moves slowly.

During a hunt, it is almost impossible for it to catch up with prey, which is why the octopus prefers to hunt from ambush.

If there is no free crevice in the habitat for arranging a “home”, octopuses choose any other “room”, the main thing is that the entrance is narrower and there is more free space inside.

Old rubber boots can serve as homes for mollusks, car tires, boxes and any other objects found on the seabed.

But, whatever the dwelling, the animal keeps it strictly clean, removing debris outside with the help of a directed stream of water.

In case of danger, octopuses tend to immediately hide and hide, releasing behind them a small stream of ink that is produced by special glands.

The ink hangs in a slowly growing stain that is gradually washed away by water.

There is another red herring octopuses vs enemies: if one of the tentacles is grabbed, the mollusk can throw it back with muscle effort.

The severed limb makes involuntary movements for some time, distracting the enemy.

The mollusks survive the cold season at great depths, returning to shallow waters with the onset of warmth. They prefer a solitary life close to other octopuses of the same size.

Thanks to developed intelligence An octopus can be tamed; moreover, it will recognize the person who feeds it among other people.

Octopus food

Octopuses eat fish, small mollusks, and crustaceans. Caribbean octopus grabs the victim with all hands, biting off small pieces.

Octopus Paule absorbs food entirely, that is, the method of feeding varies depending on the species.

Reproduction and lifespan of an octopus

The female makes a nest in a hole at the bottom, where a clutch of about 80 thousand eggs is laid. Then the nest is covered with shells, pebbles and algae.

The mother carefully monitors the eggs - ventilates them, removes garbage, is constantly nearby, without even being distracted by food, so by the time the babies appear, the female is extremely exhausted, or does not even survive until this time. Average life expectancy is 1-3 years.

The octopus is a representative of the family of cephalopods. It is popularly known as an octopus, as it has eight huge tentacles. Since ancient times, there have been many legends and myths about this inhabitant of the seas. For example, sailors believed that a giant octopus-kraken lived in the ocean, capable of dragging an entire ship under water. These representatives of cephalopods form two suborders: deep-sea octopuses (Cirrata) and true octopuses (Incirrata).

The size of most octopuses does not exceed half a meter; only the common octopus, Apollyon, Hong Kong and Doflein octopus are considered large. Some species are poisonous. They live in subtropical and tropical seas and oceans, most often in coastal rocky areas. They feed on crustaceans, mollusks and fish. Octopuses breathe through gills and can remain out of water for a short time.

Anatomy and physiology of octopuses

The octopus or octopus is a typical representative of cephalopods. Their body is compact, soft, round. The length of an adult octopus varies in the range from 1 centimeter to 4 meters. The mass of an octopus can reach 50 kilograms.

On the body of the octopus there is a mantle, which is a leather bag. The length of the mantle in males reaches 9.5 centimeters, and in females - 13.5 centimeters. An octopus has no bones. Because of this feature, it can easily change its shape and stay in a limited space.

The octopus has eight tentacles that are interconnected. A thin membrane serves as a connector. Located on the tentacles suction cups in 1-3 rows. Number of suckers adult can reach two thousand. One suction cup can hold approximately 100 grams of weight. In this case, retention occurs only due to the work of muscles, and not due to adhesion.

The mouth opening is where the tentacles grow. The mouth is equipped two strong jaws , similar to the beak of birds. The pharynx has a radula, similar to a grater, that grinds food. The anus is hidden under the mantle.

Common octopus may change color. This occurs under the influence of signals transmitted nervous system in response to external environment. IN normal condition The octopus is brown, in case of danger - white, and if angry - red.

The eyes of an octopus are similar to human ones: large with lens and an outwardly oriented retina. It is noteworthy that the pupils are rectangular in shape.

Features of the organism of octopuses

This cephalopod has three hearts: one is responsible for distributing blood throughout the body, the other two are responsible for conducting blood through the gills.

Octopus has highly developed brain and rudiments of the cortex. The shape of the brain resembles a donut. This shape allows the brain to be compactly positioned around the esophagus. Cephalopods are capable of perceiving not only ordinary sounds, but also infrasound.

Also, thanks to the huge number of taste buds, the edibility of food is determined. Compared to other invertebrates, the octopus very large genome. It has 28 pairs of chromosomes and approximately 33 thousand protein-coding genes. According to the latter indicator, the octopus is even ahead of humans.

Octopus lifestyle and behavior

Octopuses live in all seas and oceans in the tropics and subtropics. As a rule, these animals lead a benthic lifestyle alone. They prefer to settle among stones and algae. They can settle in the empty shells of other underwater inhabitants.

For living, they choose a den with a narrow entrance, but spacious inside. Cleanliness is achieved using a funnel. Garbage and leftovers are not kept inside the habitat. On a hard surface, even a vertical one, octopuses move by crawling with the help of tentacles.

If an octopus needs to swim, then to do this, the octopus draws water into the cavity where its gills are located and forcefully pushes it out in the opposite direction. If a change in direction is required, the funnel through which the water is pushed is rotated.

Any of the octopus's movement options is very slow, so for hunting the animal actively uses ambushes and color changes to obtain food.

The main enemies of octopuses are:

• dolphins;
• whales;
• sea ​​lions;
• sharks;
• seals.

In case of danger, the octopus will often flees for his life, while releasing a dark liquid from special glands. How long does this liquid remain compact in the water, allowing the octopus to hide? Some zoologists believe that these shapeless spots also act as decoys.

In addition, if a tentacle is grabbed, it can come off due to strong muscle contraction. The tentacle continues to move for some time, which allows the octopus to break away from the enemy.

Reproduction of octopuses

Breeding periods occur in April and October. In some areas the dates have been shifted and fall to June and October. An octopus mates by releasing sperm from the mantle of the male into the mantle of the female.

Female octopuses after fertilization lay eggs. For laying, they choose depressions in the ground and make a nest, covering it with shells and stones. The eggs of octopuses are spherical, united in groups of 8–20 pieces.

In one clutch there may be 80 thousand eggs. The octopus takes care of the eggs, passing water, removing dirt and foreign objects. Until the eggs hatch, the female remains at the nest without food. It happens that she even dies after the young hatch.

During the first months, newborn octopuses feed on plankton and lead only a benthic lifestyle. After a month and a half, they already reach 12 millimeters and weigh several grams, and upon reaching 4 months they weigh about a kilogram.

Of the entire clutch, only one or two individuals reach sexual maturity. The lifespan of animals can reach 4 years, but on average octopuses live 1−2 years.

What do octopuses eat?

By the nature of their feeding, bottom-dwelling octopuses are classified as lurking predators. Hidden in their shelter, they patiently watch for passing fish, crabs, lobsters, lobsters and quickly rush at them, enveloping them with their long arms. The favorite food of octopuses is Kamchatka crabs.

Having caught a crab, the octopus carries it, holding it with its tentacles like hands, to its shelter. Sometimes one octopus drags several crabs at once. Octopuses also catch large gobies and flounders. Capture of prey occurs with the help of suction cups on the tentacles. Their strength is amazing: a suction cup with a diameter of 3 centimeters can withstand 2.5-3.5 kilograms.

This is a lot, especially since these animals have hundreds of suckers. Very ingenious experiments were carried out to determine the strength of the suction cups. Octopuses kept in an aquarium were given a crab tied to a dynamometer. He instantly grabbed the crab with his hands and hurried to hide with it in the shelter, but the leash did not allow him to do this.

Then the octopus firmly attached itself to the crab and began to forcefully pull it towards itself. At the same time, he held the crab with three hands, and with the rest he stuck to the bottom of the aquarium. Octopuses weighing about 1 kilogram or more could develop a force equal to 18 kilograms.

Octopuses recognize the taste of food not with their tongue, which is converted into a grater, but with their hands. All inner surface tentacles and suckers are involved in tasting food. These sea animals have an unusually subtle sense of taste; they can even taste their enemies.

Octopuses prefer to eat:

1. Fish.
2. Crustaceans.
3. Marine animals and shellfish.

If you drop a drop of water near an octopus taken from an aquarium where a moray eel lives - worst enemy shellfish, the octopus will immediately turn purple and run away.

Like many others cephalopods, octopuses belong to carnivorous animals. They grab their food with their tentacles and kill it with poison, and only then begin to consume it internally. If the victim is caught with a shell, then the octopus breaks it with its “beak” located near the mouth.

The body of octopuses is short, soft, and oval at the back. The octopus's mouth is equipped with two powerful jaws, similar to the beak of a parrot. There is a grater in the throat that grinds food.

The octopus has three hearts: one pumps blue blood throughout the body, and the other two push the blood through the gills.

There are eight long tentacles on the head. They have from one to three rows of suckers. There are about 2000 suckers on all eight tentacles of an adult octopus!

Some types of octopuses are poisonous. Blue-ringed octopuses found off the western coast Pacific Ocean, are among the most poisonous animals in the world.

Nervous system and sensory organs.

The octopus's brain is one of the most developed among invertebrates. The brain is donut-shaped and located around the esophagus. The eyes are large, the pupil is rectangular.

Color

The octopus has the ability to change color to adapt to environment. The usual color is brown. If the octopus is scared, it turns white; if it is angry, it turns red.

Size and weight.

The lifespan of an octopus is up to 5 years. The length of adults varies from 1 centimeter to 4 meters. The mass of octopuses reaches 50 kg. The Doflein octopus can reach a length of 960 cm and a weight of 270 kg.

Nutrition.

Predators. They eat mollusks, crustaceans, and fish. The octopus captures prey with all eight tentacles. The octopus bites the victim with its beak, holding it with its suction cups. In this case, the poison from the saliva enters the victim’s wound.

Behavior and lifestyle

Most octopuses lead a bottom-dwelling lifestyle, living among stones, rocks and algae. Octopuses are less active during the day than at night, which is why they are considered nocturnal animals.

On a hard surface, the octopus moves by crawling, using tentacles with suction cups. It can also swim with its tentacles backwards - taking in water and pushing it out with force. It is inferior in speed to fish. Therefore, the octopus prefers to hunt from ambush, and tries to hide from its pursuers.

Octopuses have unusual ability- due to the absence of bones, they can change shape. Some octopuses, while hunting, lie flat on the bottom, masquerading as flounder. They can also freely fit into holes with a diameter of 6 centimeters.

Thanks to their soft, elastic body, octopuses can penetrate through holes and crevices much smaller than the normal size of their body, which allows them to hide in all sorts of shelters. They even live in boxes, cans, car tires and rubber boots. They prefer shelters with a narrow entrance and a spacious room. They keep their home clean: they “sweep” it with a stream of water, and put scraps outside in a garbage heap. When enemies approach, they flee, hiding in rock crevices and under stones.

As they flee, octopuses of many species release streams of ink, a dark liquid produced by special glands. This liquid hangs in the water in the form of shapeless translucent spots. These spots are a kind of decoys designed to divert the attention of the attacker and allow the octopus to escape.

Octopuses have protective device- a tentacle grabbed by an enemy can come off, but continue to move and distract the predator of the pursuing octopus.

Intelligence

Octopuses are considered the most “smart” among all invertebrates: they are trainable, have a good memory, and recognize geometric shapes. If you spend enough time with an octopus, it becomes tame.

Reproduction

The female makes a nest in a hole lined with a rampart of stones and shells or in a cave in shallow water, where she lays up to 80 thousand eggs. The female always takes care of the eggs: she constantly ventilates them, letting water through. She uses her tentacles to remove foreign objects and dirt.