About 300 live on our planet various kinds octopuses. They live in both the southern and northern hemispheres. These animals are not found only in fresh waters. Their life expectancy is not large - 1-2 years. Individuals who have lived for 4 years are rare and are considered long-livers. The inhabitants of cold waters are much larger than their brothers from warm seas and oceans. The smallest eight-legged mollusks do not exceed one centimeter in length, and the largest Haliphron atlanticus grow up to four meters.

Octopuses are aristocrats by blood

Octopuses have blood blue color. This is explained by the fact that in their blood is saturated with copper. The red blood, inherent in man and many other creatures, is made by iron, which is part of it.

Octopus heart affairs

Octopuses have a main heart and two secondary ones. The first, the largest, drives blood throughout the body of the mollusk. The other two, smaller, are responsible for pushing blood through the gills. Therefore, additional hearts are called gill hearts.

Tentacles like a tasting organ

Octopuses use their tentacles not only to grab objects, but also to determine palatability products. Each limb has ten thousand taste buds. And each suction cup can withstand a load of 100 grams.

Phenomenal ability to regenerate

In case of danger, the octopus can independently deprive itself of one or more tentacles without unnecessary regrets. But he does not suffer from this, and after a short period of time the missing limb grows back and functions no worse than the previous one. This technique is very similar to the maneuvers of a lizard throwing its tail. The octopus leaves a lone limb to be torn to pieces by enemies, and in the meantime, he runs away with all his might.

Octopuses are born actors

All octopuses easily change their color, disguising themselves as the environment. This is possible due to the presence in the body of molluscs of cells with various pigments, which stretch or narrow depending on the situation. In its normal state, the octopus is brown in color. A frightened octopus turns pale, sometimes becoming completely white. Angry, on the contrary, blushes, frightening the offender bright color. The color change is useful both when hunting and when playing hide-and-seek with stronger predators.

Octopuses of the species, in addition to changing color, can successfully imitate other underwater inhabitants. Thaumoctopus mimicus easily imitate jellyfish, rays or crabs.

land octopuses

Eight-legged mollusks breathe under water with gills, but a short stay in the air does not harm them. They have a wonderful device in their body - a bag for storing water. He then helps them survive the waterless period. Some species of octopus own will leaving their familiar environment. Leaning on tentacles, they move on a solid surface in search of food in small puddles left after low tide. This technique is also effective if there is a chance of becoming a dinner for a stronger opponent. There are cases when cunning mollusks made their way into the holds of fishing boats in order to feast on a fresh catch.

Mollusk with a parrot's beak

The body of an octopus is very soft and elastic. The only hard part is beak, very similar to the beak of a parrot. With this tool, like a hammer, the octopus breaks the crab shell. Due to the flexibility of the body, the octopus can squeeze into narrow gaps in rocks and reefs. The only limit is the nose. If he climbed through, then the whole octopus will slip into the hole.

Octopuses - pedants and neat

Octopuses are very responsible for cleaning their homes. Every day, they remove debris from their burrow with a jet of water that they release from the funnel of their body. They neatly store the remains of their life activity in one place near their home, thus creating a stationary trash can for waste.

Octopuses are smart

Octopuses are considered the most intelligent among invertebrates. They recognize and become attached to their owners. After not long workouts can distinguish shapes and colors. With constant contact with a person, they become completely tame.

Octopus - keen eye

Octopuses have excellent eyesight. They see well both in the light and in the dark. The pupil of these mollusks is rectangular, like that of goats.

The blind octopus loses the ability to change color. Blinded in one eye, it changes color only from the side of the healthy eye.

floating inkwell

During the chase, the octopus throws out a cloud of ink at the enemy, which completely disorients him. And while the enemy comes to his senses, the mollusk quickly leaves danger zone. Ink not only impairs visibility for attackers, but also knocks off the trail due to its specific smell. In connection with these further persecution of the victim becomes impossible.

Marriage games at a distance

Octopuses are wonderful animals, often the heroes of sea tales and myths. There are quite a few legends about mutant octopuses and killer octopuses. However, these are just speculations. Most representatives of this species are not dangerous to humans and are themselves afraid of human society. Most big octopus was caught off the coast of the United States in 1945. Its weight was 180 kilograms, and its length was 8 meters.

Octopuses: species and their taxonomy

The octopus squad (lat. Octopoda) includes two suborders: deep-sea (Cirrina) and real (Incirrina).

The deep-sea or fin suborder unites the little-known and most interesting representatives. These animals are found only in great depths. They can swim in the bottom layers of water or live at the bottom. deep sea trenches. Distinctive feature The structure of these mollusks is the presence of fins. These are small creatures, often with a bizarre appearance. This suborder includes about 34 species, 7 genera, consists of 3 orders:

- cirrhotics (Cirroteuthidae);

- opisthoteitovye (Opisthoteuthidae);

- staurotate (Stauroteuthidae).

Giant Pacific Octopus

The suborder of real or finless is the most numerous. Representatives of various types of octopuses, this suborder are famous for their large size. But among them there are many small-sized animals. They live mainly on seabed on the shallow depths sometimes close to the coast. Only a few species of this suborder live on the bottom of the oceans at a depth of up to 8 km. This suborder contains about 180 species, 35 genera and 9 families:

- seven-legged (Alloposidae);

- amphitretids (Amphitretidae);

- argonauts (Argonautidae);

— bolitenidovye (Bolitaenidae);

- Idioctopodidae (Idioctopodidae);

- octopus (Octopodidae);

- kyphoids (Ocythoidae);

- Tremoctopodidae (Tremoctopodidae);

- glass (Vitreledonellidae).

Octopus tentacles with suction cups

Spreading

Cephalopods of this order live in almost all oceans and seas of our planet. These mollusks are especially common in tropical zones, but are also found in the cold seas of the Arctic Ocean. In our country, octopuses are found in all northern seas, with the exception of the White, as well as in the Russian seas Pacific Ocean. About 25 of their varieties live here.

These invertebrates live at different depths. In shallow places, relatively close to the coast, you can often meet representatives of real octopuses. They lead the so-called "bottom" way of life. Deep sea representatives Octopoda order inhabit the depths of the oceans. These species of octopuses are perfectly adapted to exist on the ocean floor under the pressure of many kilometers of water.

Lifestyle and behavioral patterns

Most cephalopods of the Octopoda order live at the bottom of the seas and oceans. Some species constantly lead a planktonic lifestyle. They are able to swim in the water column like squids and walk along the bottom using their tentacles. live on different depths, usually up to 150 m, but deep sea species Octopuses live at a depth of several kilometers. At the bottom, these animals hide between stones or in underwater caves, and some even build their own shelter from stones and shells.

These are predators that feed on molluscs, crustaceans, echinoderms, fish, which they kill venomous bite. They hunt mainly at night. Octopuses are able to change color, becoming indistinguishable from the surrounding landscape.

The sense organs of all members of the detachment are well developed. They have good vision and a large brain. These invertebrates are different complex behavior, good memory and high intelligence. They are easily tamed and trainable. Females take care of the offspring, guarding the laid eggs.

Since ancient times, people have used cephalopods for food. The meat of many species of octopus is considered a delicacy. Therefore, in some countries they are commercially caught. In places, the number of these animals is sharply reduced due to overfishing.

Octopus - squad representative sea ​​shellfish belonging to the class of cephalopods. All individuals are characterized by a sac-like body. Further in the article we will find out the features of these animals, how many legs an octopus has. Photos of shellfish will also be given below.

Short description

The octopus has three hearts. The main thing is to move blood around the body. The rest push it over the gills. Due to the fact that hemocyanin is present in plasma and red blood cells (copper replaces iron in it) instead of hemoglobin, the blood of animals is blue. At the octopus big eyes with a rectangular pupil. The head of the animal is well developed, has a cartilaginous skull. It provides protection to the brain with a rudimentary cortex. The size of the animal is from 50 mm to 9.8 m (between the ends of the tentacles located oppositely).

Food

All octopuses are predators. Their main food is crustaceans, fish, and molluscs. The common octopus captures prey with all its tentacles. Holding the victim with suction cups, he bites her with his beak. Poison enters the wound of the prey from salivary glands. Octopuses are characterized by pronounced individual preferences in food and methods of obtaining it. The mollusk has four pairs of tentacles. How many legs an octopus has and whether it has hands, we will find out further.

Shellfish in motion

Most species live among stones, algae and rocks. A favorite hiding place for young animals on Far East for example, are empty scallop shells. Due to the fact that octopuses are more active at night, they are counted. So, how many legs does an octopus have? How does he even use his limbs? On solid, including sheer surfaces, molluscs move by crawling. In this case, all tentacles are involved. Many people think that an octopus has eight legs. However, this is not quite true. During research, it was found that the mollusk is repelled by two tentacles. To move forward, he uses the rest of the limbs. Movements "hands" are similar to those that swimmers make. A pair of hind limbs is used to move along. With their help, the mollusk also climbs underwater rocks. Thus, the number of legs in an octopus is 2, all other tentacles perform the function of hands. Due to the fact that the body of molluscs is elastic, they can penetrate through cracks and holes, the dimensions of which are much smaller than their own. This allows them to hide in all sorts of shelters.

Behavior

Many species have special glands that produce a dark liquid called "ink". In the form of translucent shapeless spots, the liquid hangs in the water and keeps compact for some time before it is washed away by water. Fleeing from someone, the octopus releases jets of ink. Zoologists today do not have a consensus about the purpose of this behavior. Researcher Cousteau hypothesized that "ink spots" in octopuses are in some way false targets for opponents, diverting their attention. Mollusks have another adaptation for protection. A clam tentacle that is grabbed by an enemy can break off. This is due to the strong muscle contraction. For some time, the severed tentacle continues to respond to tactile stimuli and move. This is another additional distraction for those chasing the octopus.

Research work

For a very long time, there was no exact answer to the question of how many legs an octopus has. Biologists from more than twenty European research centers have observed the behavior of octopuses for a long time. About two thousand data were analyzed. In the course of research, it was found that two tentacles are definitely legs. As a rule, animals move slowly. But in case of danger, mollusks can reach speeds of up to 15 km / h. The researchers note that the brain sends a signal to start moving, but each tentacle makes its own decision about its speed, nature and direction. At the same time, even those limbs that are torn off from the body continue to perform the actions programmed earlier. Biologists have also found that the octopus is equally good at the limbs of the left and right sides of the body. However, preference is still given to the third front tentacle - it is designed to bring food to the mouth. Each limb has up to 10 thousand receptors, through which the inedibility or edibility of an object is determined.

Peculiarities

After finding out how many legs an octopus has and how it uses its limbs, the researchers began to study the intelligence of animals. Animal psychologists consider these mollusks the most intelligent of all representatives of invertebrates. Such conclusions are based on practical observations. So, cephalopods have a good memory, can be trained, and are able to distinguish geometric shapes: large from small, a circle from a square, a vertical rectangle from a horizontal one. In addition, they get used to people, easily recognize those who feed them. If you spend a lot of time with an octopus, then it will become tame. These molluscs are highly trainable.

Titles: common octopus, common octopus, common Atlantic octopus, European octopus, octopus.

Area: octopuses are distributed all over the world: the Mediterranean, the Eastern Atlantic Ocean, Japanese Sea.

Description: the body of the octopus is short, soft, oval behind. The mouth opening is located at the point where its tentacles converge, and the anal opening opens under the mantle. The mantle resembles a wrinkled leather bag. The mouth of the octopus is equipped with two powerful jaws, similar to the beak of a parrot. There is a grater in the pharynx, which helps to grind food. The head bears eight long tentacles - "arms". In males, one tentacle is modified into a copulatory organ. "Hands" are interconnected by a thin membrane and equipped with suction cups. There are about 2,000 of them on all eight tentacles of an adult octopus, each of which has a holding power of about 100 g. Each "hand" has up to 10 thousand taste buds that determine the edibility or inedibility of an object. The eyes are large, with a human-like lens. The pupil is rectangular. There is no rumor. The octopus breathes with gills, however, without damage to health, it can be out of the water for a short time. The brain is highly developed, has a rudimentary cortex. The octopus has three hearts: one (main) drives blue blood throughout the body, and the other two - gills - push blood through the gills.

Color: octopus has the ability to change color, adapting to environment. This is due to the presence in his skin of cells with various pigments, which, under the influence of impulses from the central nervous system stretch or shrink depending on the perception of the senses. The usual color is brown. If the octopus is scared, it turns white, if angry, it turns red.

The size: on average up to 90 cm in length (including tentacles), the maximum length in males is up to 1.3 m, in females - up to 1.2 m.

The weight: 4.5-7 kg, Weight Limit 10 kg.

Lifespan: rarely exceeds 4 years, on average 12-24 months.

Habitat : the octopus lives in all tropical, subtropical seas and oceans (with a salinity of at least 30%), from shallow water to a depth of 100-150 m. It prefers rocky coastal zones, looking for caves and crevices in the rocks to inhabit.

Enemies: dolphins, sea ​​lions, whales, seals, moray eels, eels, sharks, birds.

Food/food: octopus predator, hunts sitting in ambush. Eats mollusks, snails, crustaceans, fish, plankton. Prey captures all eight tentacles. The octopus bites the victim with its beak, holding it with suction cups. In this case, the poison of the salivary glands from the pharynx and mouth enters the wound. Individual preferences in food and in the way it is obtained are strongly expressed.

Behavior: the octopus leads a benthic lifestyle, living among stones, rocks and algae. It is less active during the day than at night, so it is considered a nocturnal animal. Shy, when a diver or scuba diver approaches, he usually hides under the rocks. He keeps his dwelling clean: he sweeps with a jet of water from a funnel, the leftovers are put outside in a garbage heap. It drags into the hole everything that it finds at the bottom: the main thing is that the entrance is narrow, and inside it is wide. Settles even in boxes, cans, tires and rubber boots. Becomes aggressive during mating. When enemies approach, it flees, hiding in the crevices of rocks and under stones. Octopuses have a protective device - autotomy: a tentacle grabbed by an enemy can come off due to a strong contraction of the muscles, which in this case tear themselves apart. The most "intelligent" among all invertebrates: amenable to training, has a good memory, distinguishes geometric shapes. Winters in deeper waters, and migrates to shallow waters in summer.

Social structure: single, territorial Often settles next to octopuses of the same size as him.

Reproduction: the length of the mantle in adult males is about 9.5 cm, in females - 13.5 cm. An octopus can mate for several hours. During reproduction, the male removes spermatophores from the mantle cavity and transfers them to the mantle cavity of the female. The nest is a hole in the ground lined with a shaft of stones and shells. Eggs are spherical, connected in groups (8-20 pieces each). After fertilization, the female arranges a nest in a hole or cave in shallow water, where she lays up to 80 thousand eggs. The female always takes care of the eggs: she constantly ventilates them by passing water through the so-called siphon. With tentacles, she removes foreign objects and dirt. During the entire period of egg development, the female remains at the nest, without food and often starves to death.

Season/breeding period: There are two breeding peaks. In the Mediterranean and the Sea of ​​Japan, the first peak occurs in April, the second in October; in West Africa, the first peak in June, the second - in September.

Incubation: depends on temperature and egg size. On average 4-5 months.

Offspring: For the first 45-60 days, newborn octopuses feed on plankton and lead a benthic lifestyle. After forty days they reach 12 mm. In the Sea of ​​Japan, at the age of 4 months, young octopuses weigh about 1 kg. Only 1-2 young octopuses out of 200,000 survive to sexual maturity.

Benefit / harm to humans: the octopus is eaten, is a subject of trade.

The body of octopuses is short, soft, oval behind. The mouth of the octopus 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 drives 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 one to three rows sucker. On all eight tentacles of an adult octopus, there are about 2000 suckers!

Some species of octopus are poisonous. Blue-ringed octopuses living at western coasts Pacific Ocean are among the most poisonous animals in the world.

Nervous system and sense organs.

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

Color

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

Size and weight.

The life span 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. Doflein's octopus can reach a length of 960 cm and a mass of 270 kg.

Food.

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

Behavior and lifestyle

Most octopuses lead a benthic life, living among stones, rocks and algae. During the day, octopuses are less active than at night, so they are considered nocturnal animals.

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

octopuses have unusual ability- due to the lack of bones, they can change shape. Some octopuses during the hunt are flattened on the bottom, disguised as a flounder. They can also freely pass through holes with a diameter of 6 centimeters.

Thanks to their soft, elastic body, octopuses can penetrate through holes and crevices that are much smaller than their usual body sizes, which allows them to hide in all sorts of shelters. They settle even in boxes, cans, car tires and rubber boots. Prefer shelters with a narrow entrance and a spacious room. They keep their dwelling clean: they “sweep” with a jet of water, put the leftovers outside in a garbage heap. When enemies approach, they flee, hiding in the crevices of rocks and under stones.

When fleeing, 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 decoy designed to divert the attention of the attacker and allow the octopus to hide.

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

reproduction

The female arranges a nest in a hole lined with a shaft 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, passing water. Tentacles she removes foreign objects and dirt.