Child-loving mollusks: evidence of offspring care among primitive life forms. Octopus (Octopus vulgaris) Whether to take care of their offspring sand octopus

In total, there are about 300 species of octopuses and they are all truly amazing creatures. They live in subtropical and tropical seas and oceans, from shallow water to a depth of 200 m. They prefer rocky coasts and are considered the most intelligent among all invertebrates. The more scientists learn about octopuses, the more they are admired.

1. The brain of an octopus is shaped like a donut.

2. The octopus does not have a single bone, which allows it to penetrate into a hole that is 4 times smaller than its own size.

3. Due to the large amount of copper, the blood of the octopus is blue.

4. There are more than 10,000 taste buds on the tentacles.

5. Octopuses have three hearts. One of them drives blue blood throughout the body, while the other two carry it through the gills.

6. In case of danger, octopuses, like lizards, are able to discard their tentacles, breaking them on their own.

7. Octopuses camouflage themselves with their environment by changing their coloration. When calm, they are brown, frightened, turn white, and when angry, they acquire a reddish tint.

8. To hide from enemies, octopuses emit a cloud of ink, which not only reduces visibility, but also masks odors.

9. Octopuses breathe with gills, but can also spend quite a long time out of the water.

10. Octopuses have rectangular pupils.

11. Octopuses always keep their home clean, they “sweep” it with a trickle of water from their funnel, and put the rest of the food in a specially designated place nearby.

12. Octopuses are intelligent invertebrates that can be trained, remember their owners, distinguish shapes and have a simply amazing ability to unscrew banks.

13. Speaking about the unsurpassed intelligence of octopuses, we can recall the world-famous oracle octopus Paul, who guessed the outcome of matches involving the German football team. Actually, he lived in the Oberhausen Aquarium. Paul died, as suggested by oceanologists, by his own death. In front of the entrance to the aquarium, a monument was even erected to him.

14. The personal life of marine life is not too happy. Males often become victims of females, and they, in turn, rarely survive after childbirth and doom their offspring to an orphan life.

15. There is only one species of octopus - the Pacific striped, which, unlike its counterparts, is an exemplary family man. For several months he lives in a couple and during all this time he does something very similar to a kiss, touching his mouth with his soul mate. After the appearance of the offspring, the mother spends more than one month with the children, takes care of them and educates them.

16. This same Pacific striped boasts an unusual hunting style. Before the attack, he lightly pats his victim "on the shoulder", as if warning, but this does not add to her chances of survival, so the purpose of the habit is still a mystery.

17. During reproduction, males use their tentacles to take out spermatophores “from the bosom” and carefully place them in the mantle cavity of the female.

18. On average, octopuses live 1-2 years, those who live up to 4 years are long-livers.

19. The smallest octopuses grow up to only 1 centimeter, and the largest up to 4 meters. The largest octopus was caught off the coast of the United States in 1945, its weight was 180 kg, and its length was as much as 8 meters.

20. Scientists have successfully deciphered the octopus genome. In the future, this will help to establish how they managed to evolve into such an intelligent creature and understand the origin of amazing cognitive abilities. At the moment, it is known that the length of the octopus genome is 2.7 billion base pairs, it is almost equal to the length of the human genome, which has 3 billion base pairs.

Smart sea chameleons are octopuses or octopuses! “Octopus - what a horror! - Sucks you out. He pulls you towards him, and into himself; you, bound, glued, feel like you are slowly swallowed by this monster. (Victor Hugo, Toilers of the Sea). Octopuses, or octopuses, have a bad reputation as underwater monsters.

Ancient legends and fantasy stories like this passage from Victor Hugo's novel portray octopuses in a very unattractive light.

Octopuses and octopuses - sea chameleons

But in fact, even such a giant as the Pacific octopus can be up to 6 meters long and weigh almost 50 kilograms, which is usually not formidable for a person.

In recent years, various fictions and tales about octopuses as "monsters" have given way to true eyewitness accounts - divers and ocean biologists who are engaged in research on these quick-witted marine chameleons.

How octopuses hunt

Octopuses don't eat people. These sea creatures feed mostly on crustaceans. To catch prey, they use their eight tentacles and 1,600 muscular suckers. A small octopus, using suction cups, can drag an object 20 times heavier than itself! Some octopuses have strong venom. During the hunt, the octopus almost instantly paralyzes its prey, and then calmly pushes it into the mouth, which has a beak-like jaw.

But what if the octopus sees someone wanting to catch it? These creatures have one drawback: their blue blood contains hemocyanin instead of hemoglobin. Such blood does not carry oxygen well, so octopuses quickly get tired. And yet they manage to deftly escape from whales, seals and other predators.

How do octopuses defend themselves?

First, their “jet engine” comes to their aid. When the octopus sees danger, it abruptly ejects water from the cavity of its body, and the reactive force formed in this way pushes it back - away from the enemy.

This cautious creature can also resort to another trick: shoot a cloud of inky liquid at the attacker. This dye contains a pigment that is poorly soluble in sea water. Therefore, while the puffs of "smoke" disperse, the octopus has the opportunity to quietly slip to a safe place.

Octopuses are skilled camouflage

The octopus does not like to be chased by predators - he prefers to hide. How he does it? The famous underwater explorer Jacques-Yves Cousteau wrote: “In the coastal waters of Marseilles, we started shooting a film about octopuses.

However, most of our divers reported that there were no octopuses there at all, and if they were once, they have now disappeared somewhere. But in fact, divers sailed near them but did not notice them, because they know how to skillfully disguise themselves. What helps octopuses become almost invisible?

Adult octopuses have about two million chromatophores, which means that on average there are up to 200 of these pigment cells per square millimeter of body surface. Each such cell contains a red, yellow or black pigment. When an octopus relaxes or tenses the muscles around the chromatophores, it can almost instantly change color, even form various patterns on itself.

Oddly enough, but it seems that the eyes of the octopus do not distinguish colors. However, he can "paint" himself in more than just three colors. And this is because iridocytes, cells with mirror crystals, reflect light, and the body of the octopus gains color in the bottom area on which it is located. And that is not all. When hiding in a coral reef, it can even roughen its smooth skin into spikes to blend into the uneven surface of the coral.

Octopuses and octopuses are conscientious builders

Since octopuses like to hide, they build their houses in such a way that they are difficult to find. Basically, they build their dwellings in various cracks or under rocky ledges. The roof and walls are made from stone, pieces of metal, shells, and even from the remains of ships and boats, or from various rubbish.

Having such a house, the octopus becomes a good owner. With jets of water from his "jet engine", he smoothes the sandy floor. And after eating, all the leftovers are thrown out of the house.

Somehow, divers from the Cousteau team decided to check whether the octopus really does a good job in the house. For this, several stones were taken from the wall of his dwelling. What did the owner do? Finding suitable cobblestones, he gradually built a wall!

Cousteau wrote: “Octopus worked until he restored what was destroyed. His cabin looked exactly the same, as did the interventions of the divers.” Indeed, octopuses are known for being able to build their own dwellings well and keep them in order. When divers see an octopus house full of rubbish, they know that no one lives there.

Octopuses and octopuses - breeding

The last and most important home in the life of a female octopus is the place where her offspring is born. Having received sperm from the male, the female retains it in her body until the caviar matures and becomes ready for fertilization. However, all that time she does not sit idly by, but spends several weeks looking for a suitable place for a nest.

When the house is ready, the female attaches a bunch of thousands of eggs to the ceiling. Only blue-winged octopuses don't make houses. Their bright coloring warns predators: our bite is very poisonous. Therefore, females prefer to take care of their offspring in open areas.

Female octopuses are caring mothers! After laying eggs, mother octopus stops eating because new responsibilities have appeared. She relentlessly protects, cleans and rinses the eggs, repairs her nest, and when predators swim up, she assumes a threatening posture and drives them away.

The female takes care of the eggs until little octopuses come out of them. After that, she dies. Cousteau once said about this: "Nobody has yet seen a female octopus leave her caviar."

Newborn octopuses of most species float to the surface of the sea and become part of the plankton. Many of them will be eaten by other sea creatures. But after a few weeks, the survivors will return to the bottom and gradually turn into adult octopuses. Their life expectancy is almost three years.

Are octopuses smart and savvy?

Some people think that if we say “smart” about an animal, then this only applies to its ability to learn from its own experience and the ability to overcome some kind of difficulties.

And here is what Cousteau said about this: “Octopuses are shy, and this is precisely their “wisdom”. They all come down to caution and prudence ... If a diver manages to show that he is not a threat, then the octopus quickly, even faster than other "wild" animals, forgets about his fearfulness».

Among invertebrates, octopuses have the most developed brain and eyes. Eyes, like ours, can focus accurately and respond to changes in light. The area of ​​the brain responsible for vision deciphers the signals coming from the eyes, and together with the wonderful sense of touch, helps the octopus make amazingly wise decisions.

Researchers have reported that octopuses even manage to open bottles to get their favorite dish - shellfish. It is said that the octopus can learn to unscrew the lid on the jar to get food from it. And the octopus from the Vancouver Aquarium (Canada) every night made its way through the drainage pipe to neighboring reservoirs and caught fish there.

In the book Exploration of the Secrets of Nature (English), about the ingenuity of octopuses, it is written: “We used to think that primates are intelligent among animals. But there is a lot of evidence that octopuses are also among the smart animals.” These creatures are a real wonder. Both scientists and divers, unlike Victor Hugo, no longer use the word “horror” about them.

Those who study octopuses have every reason to admire and wonder at this quick-witted marine chameleon.

An octopus species unknown to science. The unusual creature was nicknamed Casper for its milky color and resemblance to the Disney character.

Marine biologists have come to the conclusion that due to a number of differences from their relatives, we can talk about the discovery of not only a new species, but also a whole new genus of octopuses. The fact is that this octopus lives at an incredible depth for cephalopods - more than four thousand meters. Casper has no fins, and all suckers are arranged in one row on each limb, which is also uncharacteristic of octopuses. In addition, the representative of the new species completely lacks pigment cells - chromatophores. That is why the creature is almost transparent.

A team of scientists led by Autun Purser from the Institute of Polar and Marine Research. Alfred Wegener, observed 30 individuals using remote-controlled underwater vehicles.

The discovery made by scientists turned out to be surprising and frightening at the same time. They were able to find out that "ghostly" octopuses are characterized by an unusual parenting strategy. She would be a real gift for the scientific community, if not for one thing: it is because of her that a unique species is threatened with extinction.

Female "ghostly" octopuses take care of the eggs until the offspring hatch. Due to the low temperatures prevailing at great depths, this happens for quite a long time - sometimes up to several years (although after scientists it is already difficult to surprise with the timing).

At the same time, the researchers note that the strategy of caring for offspring, as the researchers note, turned out to be incredibly touching in these octopuses: the female wraps her whole body around the eggs and protects them from other deep-sea inhabitants, without even sailing off to get her own food. As a result, almost always she dies when the cubs hatch.

But this was not the main threat to the new species. Observations have shown that "ghost" octopuses are accustomed to laying eggs on dead sponges - these are deep-sea multicellular organisms leading an attached lifestyle. Near the Hawaiian Islands, where Casper was first seen, these sponges attach themselves to deposits of ferromanganese nodules - formations that contain a large amount of valuable metals (manganese, copper and nickel), which are used, for example, in the manufacture of mobile phones.

Areas of the ocean floor covered with such deposits. In this regard, the territory for breeding octopuses is under threat.

Casper's relatives are recognized as long-lived, which means that if the concretions and sponges living on them disappear completely, it will be almost impossible to restore the "ghostly" octopus population. According to scientists, if this region is used for industrial purposes, the local fauna will not recover even 26 years later. This, in turn, will harm the ecosystem as a whole, as octopuses feed on small organisms, whose populations will increase unpredictably when the former disappear.

Scientists suggest that octopuses prefer to lay eggs on sponges near manganese deposits due to the connection with the source of food, and also because of the safety of such locations (from the point of view of the daily life of the ocean), but this is only a hypothesis that needs to be tested.

So far, very little is known about the "ghostly" octopuses, and marine biologists intend to protect the ecosystem and the rare species from extinction, because its further study can provide valuable information. In addition, many more unknown creatures can live at great depths, which will also suffer from anthropogenic activities.

Researchers from California found that octopuses can care for eggs in the nest for four and a half years - longer than other known animals. During this time, the female octopus takes care of her offspring, constantly cleaning the eggs from dirt and protecting them from predators. Often, with a lack of food, she dies after the juveniles hatch from the eggs.

Scientists at MBARI have been surveying the ocean floor every few months for the past 25 years, observing the life of deep-sea animals in the Monterey Canyon region. During one of these dives in May 2007, experts found a female octopus at a depth of 1.4 thousand meters on one of the rocky ledges. It was a representative of the Graneledone boreopacifica species. She hadn't been here a month before.

Over the next four and a half years, the researchers made 18 dives in this place. Each time scientists could observe the same octopus (biologists identified it by special markings). A few years later, the translucent eggs laid by the female increased in size, and experts were able to see small octopuses inside. After four years, the female lost weight and her skin became pale. During the dives, the researchers never saw the female eating. Moreover, she did not even show interest in small crabs and shrimp passing by.

The last time the scientists saw the female was in September 2011. A month later, the octopus was gone. Judging by the remaining egg shells, the young octopuses have recently hatched and the female has left the area. After counting the remains of the eggs, the researchers concluded that there were about 160 of them.

Most female octopuses lay eggs only once in their lives. The eggs of Graneledone boreopacifica are teardrop shaped. They are about the size of small olives. The small octopus needs a lot of oxygen inside the egg, so the female must constantly provide fresh water to the nest, preventing dirt and silt from entering it.

Because young octopuses spend a lot of time in the egg, they hatch fully developed. After hatching, they can already hunt small prey on their own. The hatched juveniles of Graneledone boreopacifica are better developed than other octopus and squid species. Octopus eggs, like many other invertebrates, are in cold sea water, which slows down their development. The water temperature at the depth of Monterey Canyon is about 3 degrees Celsius.

In the art of disguise, he has no equal. Is he capable of thinking? Does he have consciousness? Some scientists believe that this is quite possible.

Imagine that you are diving into the sea off the coast of the Indonesian island of Lembeh. It is not deep here - about five meters, and everything is flooded with sunlight. The water is very warm - as expected in a tropical paradise. The bottom is covered with wavy fine dark gray sand with greenish spots of silt. Looking around the surroundings, you notice a lone bivalve, quite massive. Six sharp spikes protrude from it: perhaps the owner of the shell is hiding inside. Or maybe he died a long time ago, and now a hermit crab has settled in the bivalve. Out of curiosity, you decide to turn the shell over... But instead of the horns of a snail or the stalked eyes of a cancer, large, almost human eyes, surrounded by a halo of tentacles with suction cups, look at you. Here is an octopus, namely the coconut octopus (Amphioctopus marginatus), so named for its fidelity to the coconut shell - it is in it that he prefers to hide. Sometimes this mollusk even travels with its shelter - after all, it may well come in handy in case of danger. However, if an empty shell comes across, it will take it.

"These animals are walking pieces of meat, a kind of filet mignon in the depths of the sea."

Having secured with suction cups, the octopus gently holds the flaps. You continue to watch and notice that, slightly loosening his grip, he pulls himself up and sticks out: he assesses the situation. Pausing so as not to frighten off a thumb-sized mollusk, you see how he, making sure that there is no danger, leaves the shell. Moving along the sand, the octopus becomes as dark gray as the ground. Has he decided to leave? Not at all: crawling along the sand, the mollusk climbs onto the shell. Then, with a deft movement, he turns it over and crawls inside again. You were about to set sail when suddenly a barely perceptible movement catches your eye: an octopus washes away the sand under the sink with streams of water until a gap forms there. And now our hero is already peeking out from under the shell. You lean closer and your eyes meet. He looks into your eyes, as if studying. Yes, among invertebrates, octopuses are perhaps the most human. Even among vertebrates, such an intelligent, searching look is rare: try to imagine some kind of fish trying to look into your soul!

The spots on the body of the nocturnal octopus Callistoctopus alpheus are pigment-filled sacs. If the clam decides to reveal them all, its skin will be covered with a pattern of white polka dots on a red background.

Octopuses resemble humans also in that they are famous for their agility - with the help of tentacles strewn with hundreds of suction cups, they can manipulate objects no worse than we do with our fingers, easily open bivalve shells, screw lids off jars and even disassemble the water filtration system in aquariums. This distinguishes them favorably from marine mammals, because the same dolphins, although smart, are very limited by the anatomy of the body - with all their desire and ingenuity, they cannot open a jar. At the same time, it is difficult to imagine creatures more unlike us: did you know that an octopus has three hearts and blue blood? And about the fact that they do not have a skeleton? A beak like a parrot's and thick cartilage protecting the brain are all hard parts of the body. Therefore, they easily penetrate through cracks and can escape from almost anywhere. And each sucker is able to move independently of the others and is covered with taste buds - as if the human body were studded with hundreds of tiny tongues. And in the skin of the mollusk, a lot of light-sensitive cells are concentrated. But this is not the most alien quality of cephalopods. Before we reveal all the cards, let's get to know the representatives of this tribe closer. If humans belong to the class of mammals, then octopuses are also included in the class of cephalopods (Cephalopoda). The name of the class perfectly reflects the essence of their anatomy: “legs”, that is, tentacles, are located on one side of a large head, grow from it, and a short sac-like body is on the other. The class Cephalopoda refers to the phylum Mollusca, which also includes gastropods (snails and slugs), bivalves (mussels and oysters), multivalve chitons, and several lesser known classes. Their history goes back half a billion years and begins with a tiny creature with a cap-like shell. After 50 million years, these mollusks already dominated the ocean, turning into the largest predators. Some individuals reached enormous sizes - for example, the length of the shells of a giant endocer (Endoceras giganteum) exceeded five meters. Now the planet is inhabited by more than 750 species of cephalopods known to science. In addition to 300 species of octopuses, this class includes squid and cuttlefish (having 10 tentacles each), as well as several types of nautilus - unusual mollusks with nine dozen tentacles that live in a multi-chambered spirally folded shell. Representatives of this genus are the only direct descendants of the oldest outer-shell cephalopods.

Modern octopuses are very diverse: from the giant North Pacific octopus (Enteroctopus dofleini), in which only one tentacle can reach two meters in length, to the tiny Octopus wolfi, whose mass does not exceed 30 grams. Shallow-water species prefer to settle among corals, stay in muddy pools or hide in the sand, surfacing only to get from one point to another, or to escape from predators. Views of the open sea cut through the expanses of the sea, following the ocean currents. They are found everywhere - from the tropics to the polar regions. Let us return, however, to the shores of the island of Lembeh. A new day is just beginning, the sun's rays penetrate the water column. You are sailing over a shallow coral reef. The local guide Amba gives you a sign that he has noticed an octopus, and quite a large one. You look around, trying in vain to see the mollusk, but you see only rocks covered with coral and colorful sponges. Amba insists, gesticulating "Big!". You look where he points his finger, but you don't see anything. However, looking at the dark velvety coral one more time, you understand that this is not a coral at all, but a blue octopus (Octopus cyanea). And how did you not immediately make out this creature, the size of a serving dish! Many animals hide, merging with the objects around them - for example, that orange sponge over there is actually not a sponge at all, but an angler fish, hiding in anticipation of careless prey. A leaf floating near the bottom is not a leaf at all, but also a fish pretending to be a leaf. The bright anemone is by no means a poisonous polyp, but a harmless sea slug, cleverly confusing everyone with its appearance. But a small section of the seabed suddenly took and swam - in fact, this is a flounder, merged in color with the ground. But even in such a company, octopuses and cuttlefish (and, to a lesser extent, squid) have no equal in the art of disguising themselves on the go, or rather, afloat - sometimes they look like a coral, sometimes like a ball of snakes, and the next minute they can no longer be seen on the sandy bottom. They adapt so skillfully to the surrounding objects that it seems as if they create three-dimensional images of various objects with the help of their body and skin. How do they do it?

Photo: Many species of cephalopods are venomous to varying degrees, but the venom of the southern blue-ringed octopus Hapalochlaena muculosa can be fatal to humans. Author: David Liittschwager; photo taken at Pang Quong Aquatics, Victoria, Australia">

Many species of cephalopods are venomous to varying degrees, but the venom of the southern blue-ringed octopus Hapalochlaena muculosa can be fatal to humans.

Photo: David Liittschwager; photo taken at Pang Quong Aquatics, Victoria, Australia

Photo: A Pacific red octopus (Octopus rubescens) displays its suckers. Each of them can move independently of the others, bend and twist to provide tight suction, impressive strength and enviable agility. Posted by David Liittschwager, photographed at Dive Gizo, Solomon Islands">

A Pacific red octopus (Octopus rubescens) displays its suckers. Each of them can move independently of the others, bend and twist to provide tight suction, impressive strength and enviable agility.

Photo: David Liittschwager, taken at Dive Gizo, Solomon Islands

Photo: Most octopuses grow very quickly - the photo shows a young blue octopus (Octopus cyanea). By David Liittschwager, photographed at Dive Gizo, Solomon Islands">

Most octopuses grow very quickly - the photo shows a young blue octopus (Octopus cyanea).

Photo: David Liittschwager, taken at Dive Gizo, Solomon Islands

Octopuses have three degrees of protection (camouflage). The first is color mimicry - pigments and reflectors are used for it. The pigments are granules of yellow, brown and red and are found inside numerous sacs in the top layer of the skin (there may be several thousand of them and look like tiny specks when closed). To change color, the mollusc contracts the muscles around the pouches, squeezing them outward, where they expand. Deftly controlling the size of the pouches, the octopus is able to change patterns on the skin - from spots to wavy lines and stripes. Reflector cells are of two types: the first simply reflect the rays falling on them - in white light they are white, in red light they turn red. Cells of the second type are similar to the film of a soap bubble: they shine in different colors depending on the angle of incidence of the light rays. Together, the pigments and reflective cells allow the octopus to create a full palette of colors and complex patterns. The second element of the camouflage system is the texture of the skin. By using certain muscle groups, octopuses easily turn a smooth body surface into a bumpy or even spiked one. For example, prickly abdopus (Abdopus aculeatus) imitates algae so plausibly that it is almost impossible to distinguish it from a plant without some skill. The third secret, thanks to which octopuses manage to remain unnoticed, is a soft body that can turn into anything. For example, curl up into a ball and slowly move along the bottom, depicting a piece of a coral reef: “They say, I’m not a predator, but just a lifeless block.”

I wonder if octopuses understand what needs to be portrayed at any given moment? An ordinary freshwater snail has about 10,000 neurons, lobsters have about 100,000, and jumping spiders have 600,000. Bees and cockroaches, leading in terms of the number of neurons among invertebrates - naturally, after cephalopods - have about a million. The nervous system of the common octopus (Octopus vulgaris) consists of 500 million neurons: this is a completely different level. In terms of the number of neurons, it significantly exceeds mice (80 million), as well as rats (200 million) and may well be compared with cats (700 million). However, unlike vertebrates, in which the majority of neurons are concentrated in the brain, in cephalopods, two-thirds of all nerve cells are concentrated in the tentacles. Another important fact: the higher the level of development of the nervous system, the more energy the body spends on its functioning, so the benefits should be worth it. Why do octopuses need 500 million neurons? Peter Godfrey-Smith is a philosopher by training, but is currently studying octopuses at the City University of New York and the University of Sydney. He believes that the appearance of such a complex nervous system is due to several reasons. Firstly, this is the structure of the body of octopuses - after all, the nervous system is transformed as the whole organism develops, and the body of an octopus is extremely complex. The mollusk can turn any part of the tentacle in any direction it likes (it has no bones, which means there are no limiting joints). Thanks to this, octopuses have complete freedom of movement. In addition, each tentacle is able to move independently of the others. It is very interesting to watch the octopus during the hunt - it lies on the sand with spread tentacles, and each of them carefully examines and searches the area allotted to it, not missing a single hole. As soon as one of the “hands” stumbles upon something edible, such as a shrimp, two neighboring ones immediately rush to the rescue so as not to miss the prey. The suckers on the tentacles can also move independently of each other. Add here the need for constant monitoring of skin color and texture; processing a continuous stream of information coming from the senses - taste and touch receptors on the suckers, organs of spatial orientation (statocysts), as well as from very complex eyes - and you will understand why cephalopods need such a developed brain. Octopuses also need a complex nervous system for navigation, because their usual habitat - coral reefs - has a rather complex spatial structure. In addition, mollusks do not have a shell, so you have to constantly be on the alert and watch out for predators, because if the camouflage suddenly doesn’t work, you will need to “do your feet” right there to take cover in the shelter. “These animals are walking pieces of meat, a kind of filet mignon in the depths of the sea,” explains Mark Norman, a world-class expert on modern cephalopods from the Victoria Museum in Melbourne, intelligibly. Finally, octopuses are fast, agile hunters with a wide range of taste preferences. They eat everything from oysters hiding in powerful shells to fish and crabs, which themselves are not a miss: with strong claws or with sharp teeth. So, a boneless body, a difficult habitat, a varied diet, the need to hide from predators - these are the main reasons, according to Peter Godfrey-Smith, that led to the development of the mental abilities of cephalopods. Being the owners of such a developed nervous system, how smart are they? Assessing the level of intelligence of animals is not an easy task, often in the course of such experiments we learn more about ourselves than about the individuals being studied. Traditional traits that measure the intelligence of birds and mammals, such as the ability to use tools, do not work in the case of octopuses, because the main tool for these mollusks is their own body. Why does an octopus need to make something to extract a treat from a hard-to-reach crevice or use foreign objects to open an oyster? For all this, he has tentacles. Tentacles are tentacles, but back in the 1950s and 1960s, scientists began to conduct experiments during which they found that octopuses are highly trainable and have a good memory - and these are two main signs of intelligence. Roy Caldwell, who studies octopuses at the University of California (Berkeley), says: “Unlike the smartest common octopus (Octopus vulgaris), many of my charges turned out to be dumb as Siberian boots.” - "Who is it?" - you ask. “For example, tiny Octopus bocki.” “Why are they so underdeveloped?” “Probably because they don’t have to deal with difficult situations in life.”

David Liittschwager, photographed at Queensland Sustainable Sealife, Australia Callistoctopus alpheus is propelled forward by a jet of water released by the muscles of the mantle through a funnel located just below the eye.

It doesn't matter if octopuses are smart or stupid, whether they think about food or think in spiritual categories - in any case, there is something special about them. Something mesmerizing and alluring. ...There is one more dive left. Sunset time on Lembeh island. You stopped at the bottom of a rocky slope. A couple of fish are swimming in front of you, they are spawning. Not far from them, an eel curled up in a burrow. A large hermit crab slowly drags its shell, and it taps dully on the bottom. A small octopus hid on a rock. You decided to take a closer look at him: here he begins to move slowly, for a moment hangs in the water column, like an eight-armed yogi. Then he goes about his business again. Now he has already crossed the rock, but you still could not see exactly how he moves - whether he pulls himself up with his front tentacles, or pushes himself off with his back ones. Continuing to move, the mollusk gropes for a small crevice and instantly disappears there. Well, gone. No, not really: a tentacle protrudes from the gap - it checks the space surrounding the mink, grabs a few pebbles and seals the entrance with them. Now you can sleep peacefully.