Octopuses are the most famous cephalopods, but, nevertheless, hiding 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 the octopus is called the mantle; on the front side it is fused with a large head, on the upper surface of which there are 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 the octopus are long and muscular, their bottom surface dotted 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 heads), but also complexly arranged. 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 throughout the skin of octopuses, which allow them to determine the general direction of light. 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 pigment, 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 color change of octopuses is directly related to color environment, 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. IN calm state 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!
Habitat various types Octopuses cover almost the entire world, only you won’t find them in the polar regions, 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 hunt. 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 dark time days, they sleep with their eyes open (they only constrict their pupils), and in their sleep the octopuses turn yellow.
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 fact, only the largest species demonstrate a threat reaction to scuba divers 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 not only... The liquid affects nerve receptors, for example, it deprives predatory moray eels of smell for a while, there is a known case when the liquid got into the eyes of a scuba diver and changed his color perception, a person saw for several minutes all in yellow color. 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.
A swimming giant octopus moves with the back of its body forward and its head backward.
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 fur 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 basic 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. At good care 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.
Octopuses are cephalopods. There are 200 different species in the order of animals “octopuses”. Their closest relatives in this type are considered to be squid and cuttlefish. The most distant include all gastropods and bivalves.
Octopus appearance
At first glance, its appearance may be puzzling. But in the end everything turns out to be simple and clear, where he is and what parts of his body are located. The body itself is shaped like a bag and is called the mantle. In front it is connected to a large head with two bulging eyes located on it. Their mouth is very small. Around the mouth chitinous jaws, which are called a beak. With the help of this beak, octopuses grind food, because they cannot swallow it whole. In addition, a little further in the throat, they have a special grater. With this grater, octopuses grind food that has not yet been chewed with its beak into pulp. The anus is hidden under the mantle.
There are tentacles around the mouth, of which there are always 8 pieces. The tentacles of the octopus are very long and with muscles, and are covered below big amount suckers different sizes. Suckers are located on the tentacles in 1-3 rows. With one suction cup alone, due to the work of the muscles, without taking into account adhesion, the octopus can hold approximately 100 grams of weight. The tentacles are united by a small membrane called the umbrella. About 20 existing species Octopuses have small fins on both sides. In these species, the fins are used as a rudder, and not for pushing off the water and moving around.
Under the eyes of the octopus is siphon, which looks like a short tube or small hole. Using a siphon, water is drawn into the mantle cavity. Using the contraction of the mantle muscles, the octopus forcefully pushes water out of the mantle cavity, which moves its body. To change direction, he turns the siphon and pushes the water in the other direction. On a hard or vertical surface in water, octopuses move by crawling, using tentacles.
They have blood blue color due to hemocyanin. This is a special pigment that replaces hemoglobin. Gills are hidden in the mantle cavity and are necessary not only for breathing, but also for excreting waste products. They also have a special ink sac that accumulates a protective coloring substance.
The largest octopuses grow up up to a length of 3 meters and 50 kilograms of weight. The most common types are from 0.2 to 1 meter in length. The only exceptions are males from the Argonaut species. They are much fewer females of their own species, rarely grow even to a length of 1 cm.
Due to the lack of bones, these animals can easily change shape and stay in confined spaces.
Octopus sensory organs
Among invertebrates Octopuses are considered the most highly intelligent. All their senses are highly developed. The most perfect among the body parts are the eyes. They are not only large in size, but also very difficult to work with. Fundamentally, the method of image formation in the eyes of an octopus and a person does not differ. The octopus sees its own image with each eye. But if necessary, in order to look at something more closely, they can bring their eyes closer and focus on the object.
Corner vision their bulging eyes almost extend to 360 degrees. The eyes contain a lens with an outward oriented retina. The shape of the pupils is rectangular. The skin is all covered with light-sensitive cells, by which they can determine which direction the light is coming from.
Taste receptors are located on the suction cups, on the tentacles. Special bodies They do not have hearing, but they have the ability to hear infrasounds. Their skin is usually brown, red or yellow. Although, depending on the situation, they can change skin color like chameleons. The principle of color change is the same as in reptiles. The current color is directly dependent on the well-being or mood of the animal, as well as on the environment. When frightened, his skin becomes paler, and when angry it can turn red or even blacken.
An interesting fact is that the change coloring has a direct dependence on visual perception. If you blind an octopus, it will lose the ability to change color. If you blind him in one eye, he will change color only on the side of the body on which he sees. Tactile, light-sensitive cells on the skin also play a small role.
These animals bear offspring only once in their lives. The periods when they breed fall in April and October. In some cases, the dates are shifted and fall into June and October. Although they live on average no more than 2 years. Some time before the mating season in males, one of the tentacles transforms into an organ necessary for reproduction. This organ is called " hectocotylus".
Using your new organ, the male transfers the reproductive cells into the mantle cavity of the female. After this, the female lives for several more months ordinary life. Only after a long time does she begin to lay eggs. In one clutch there may be a large number of eggs: from 40 to 190 thousand pieces.
After laying eggs, the female becomes the most caring animal towards her future children. Sometimes the female has to wait up to 4 months for the larvae to appear. All this time she does not leave the eggs, cleans them of debris and protects them from other sea animals. It often happens that a female, exhausted from hunger, cannot stand it and dies. Males, after they pass on male reproductive cells, also die.
Larvae that hatch from eggs are already independent from the first days of life.
What do octopuses eat?
Basic food for octopuses are the following types sea animals:
- Fish;
- crustaceans;
- shellfish
Based on their feeding method, benthic species can be classified as lurking predators. They use this type of hunting, since octopuses are not adapted to move or swim quickly. Hiding in a secluded place, they wait with great patience for some fish, crab, lobster or lobster to swim nearby. Then, at the right moment, they suddenly rush at them, enveloping them with their tentacles. So that you can’t escape anymore.
Kamchatka crabs are their favorite food. Having caught the crab, the octopus pinches it with its tentacles from all sides and takes it to its shelter. There are times when an octopus manages to catch and drag away several crustaceans at once. They also prefer to hunt bulls and flounders. Using suction cups on the tentacles, they capture prey. One suction cup with a diameter of about 3 centimeters can support 3 kilograms. And since the octopus has hundreds of these suckers, the force will be great.
All species of these cephalopods belong to predatory animals. Before eating their prey, they capture it with their tentacles and kill it with poison. Animal shells are broken by the beak, which is located near the mouth. Also, each octopus has very distinct preferences in food and in the methods of obtaining this food.
The main enemies of octopuses
The main enemies include the following animals:
- Dolphin;
- sea lion;
- seal;
- moray eel;
- shark;
- bird;
- a larger individual.
If the octopus senses or notices an enemy, it will first try to defend itself. Firstly, it will try to “escape” on half-bent tentacles or slowly swim away. If he is scared, he can jerkily increase his speed up to 15 km/h. Then it will look for somewhere to hide or camouflage itself by changing its color. They camouflage themselves into the surrounding landscape even when they are not in any danger. If the soil is soft, they bury themselves in the sand. If the fear is very strong, then a dark-colored liquid is released, with the help of which the enemy is disoriented. Can sacrifice a tentacle to an enemy if it is grabbed and there is no way to escape.
Octopuses are antisocial creatures. But by a strange whim of nature, sex in some species has evolved into an extremely intimate and at the same time dangerous activity, our correspondent found out.
Male octopuses have a serious headache: females. Males, of course, want to reproduce and pass on their genes to new generations. However, females are often larger and hungrier than their partners, which is why the male has a fairly high chance of turning from a lover into a dish at a romantic dinner.
Octopus sex: everything is very unpredictable
But for every cunning lady there is a tentacle with a screw. Some species of octopuses have sex at arm's length. Males of other species sneak into a girlfriend’s bedroom in a girl’s guise, and some are even ready to give her their genitals for good.
All this is quite sad and, moreover, paradoxical. Octopuses are one of the most antisocial and unfriendly creatures in the animal kingdom, but as a result of evolution, their fertilization technique has turned out to be very intimate: the male must deposit sperm inside the female using one of his limbs. The process of octopus copulation is interesting not only in itself, but also as an illustration of how octopuses evolved to their modern state.
Octopuses and their close relatives squids are grouped into the class Cephalopods. It belongs to a type of mollusk, that is, the octopus is related, albeit more distantly, to oysters and mussels. However, nature saved the octopuses from shells.
Octopuses do not have warm feelings for each other. Unlike social animals like dolphins, they view their own kind primarily as competitors. Or as food.
The male risks his life by delivering his sperm inside the female.
In comparison, squids are downright sociable guys. But they copulate in a completely unromantic way: the male, swimming by, quickly releases sperm near the female’s body. She later decides whether to accept the gift.
Things are not so simple for octopuses. “The process of copulation in octopuses is very different from that of other cephalopods,” says marine biologist Joan Boal from Millersville University in Pennsylvania. The male, delivering his sperm inside the female, risks his life.
"To be eaten for them real threat"Explains Richard Ross of the Steinhart Aquarium at the California Academy of Sciences.
We don't know exactly how often female octopuses eat males. But Christine Huffard, who works at research institute Monterey Bay Aquarium in California, I saw this more than once.
In one case, Huffard and her colleagues observed large blue octopuses mating on a reef in Indonesia. After about 15 minutes of sexual intercourse, the female suddenly engulfed her partner’s mantle (the so-called leather bag in which the octopus’ body is enclosed) with two tentacles. After a few minutes, the male stopped moving, after which the female dragged the corpse to her lair, where she probably ate it.
In another case, researchers observed a large female great blue octopus in the Micronesia region. The small male copulated with her 12 times, but the number 13 turned out to be truly fatal for him: the partner was strangled and taken to the hole, providing the female with a food supply for the next two days.
Even when he dies, the suitor manages to fertilize a certain number of the female’s eggs
Such sexual cannibalism is not unique in nature. Female praying mantises also eat males, as do black widow spiders. But strangulation of a sexual partner, according to Ross, is a rather rare practice. However, male octopuses probably shouldn't despair.
Huffard and colleagues, describing in 2014 in their scientific work one of the cases of octopus cannibalism, it was noted that the deceased suitor seemed to have managed to fertilize a certain number of the female’s eggs. This means that he has completed his life's task. In addition, female octopuses, as a rule, produce hundreds and even hundreds of thousands of eggs, meaning that just one successful copulation can produce a great many offspring.
The tool used by the male octopus for the purpose of procreation is a special sexual tentacle - the hectocotylus. Outside of the copulation process, this tentacle works in the same way as the other seven: it is capable of bending, stretching and sucking. But this is no ordinary limb.
To begin with, there is a hollow canal running through it, through which the male tries to deliver “packets” of sperm (spermatophores) inside the female. The tip of the tentacle consists of erectile tissue, somewhat similar to the tissue of the human penis - this makes it easier to insert into the female. The hectocotylus is inserted through one of two siphon openings into the mantle cavity of the female. These same siphons are used for breathing, getting rid of waste products and as water jets when moving.
The spermatophores must enter the female's small oviductal gland, this is a kind of storage facility. When the female lays her eggs - which can happen several days or even months after copulation - they will pass through this zone and be fertilized.
Some prefer sex at a distance - because it is very dangerous!
The male needs to hold the genital tentacle inside the female for a period of time sufficient to transfer at least one spermatophore, and preferably several at once. In smaller species of octopus, the process takes only a couple of minutes, says Jennifer Mather of the University of Lethbridge in Alberta, Canada. But the giant octopuses living in Pacific Ocean, sexual intercourse can last at least half an hour.
For soft-bodied mollusks, however, it is dangerous to indulge in carnal pleasures for too long. "By curling up in a ball during copulation, they become very, very vulnerable to predators," Mather explains.
As a rule, the male initiates mating. Then the boyfriend chooses one of two behavioral tactics.
The first one is quite risky. "The male wraps all of his limbs around the female's mantle and inserts his genital tentacle into the mantle," Huffard said.
This method of copulation is preferred by octopus species with short tentacles, the expert says. Females of these species may be less likely to eat males. It seems that those species of octopus, whose males are more likely to become a post-coital snack, have evolved to grow longer tentacles - to make sex somewhat safer.
More cautious species prefer not to rush headlong at their partner, but to carefully reach out to her. “The male positions himself close to the female and reaches out to her with just his genital tentacle,” says Huffard.
In Argonaut octopuses, after sexual intercourse, the male sometimes loses one tentacle. It's better than being eaten
Thus, the male manages to stay at a distance. "The male extends the hectocotylus as far as he can, trying to mate as far away as possible," Boal explains.
This tactic is common among long-limbed octopuses, which may be more susceptible to intersexual cannibalism. The impressive hectocotylus allows the male to reach the lair of a resting female without even swimming inside.
One of these cautious species is the walking octopus. “The males have a very long sexual tentacle,” says Huffard. “During mating, it stretches to twice its normal length.” To be even more on the safe side, "these octopuses also often copulate with females while they are busy searching for food." During such periods, females are probably too busy to attack.
The remote mating method also allows the remaining seven tentacles not to be used - they can be used for defense if necessary, Ross notes.
This method is also good for the female: in theory, she can have sex with two partners at the same time, says Huffard - one for each siphon.
Males of some species act even more inventively. They simply give the female a hectocotyl filled with spermatophores and swim away.
Male Argonaut octopuses are smaller than females. Their hectocotylus remains inside their partner's mantle "until the female is ready to use the sperm for fertilization," Mather says.
In big blue octopuses, sometimes everything ends tragically for the male
For webbed octopuses, a detachable sex tentacle has become a logistical necessity. Their females reach two meter size, and males are only a few centimeters long. "They detach the tentacle that contains the sperm, and that tentacle goes into the female's mantle cavity," Ross says. "It's a pretty extreme way of avoiding being eaten."
But not all octopuses have sex that involves brutal strangulation and dismemberment. Walking octopuses are a little more tolerant of their own kind than other species, and therefore their mating behavior is somewhat more complex.
Males of this species, when attempting to copulate, must be wary of not only females, but also other males. The largest of them often guard their chosen one and mate with her repeatedly. Smaller contenders are not able to drive them away and they understand this. “Males change mating tactics depending on their chances of winning fights with competitors,” says Huffard.
The small male waits until the large one leaves the den and copulates with his partner secretly. Sometimes they even pretend to be females, hiding their hectocotyles - in order to get as quietly as possible to the protected target.
In general, we don't have a very good understanding of octopus mating habits. Maybe that's why they seem so strange to us
This cunning tactic, however, sometimes backfires, and Huffard documented it on video. The nosy male approached the den, in which, in his opinion, the female was hiding. As soon as he extended his sexual tentacle into the hole, an octopus emerged. But it was not the octopus, but her bodyguard, who did not at all like Casanova’s attempt to insert a hectocotylus into his robe. The nimble little fellow barely escaped the impending thrashing with his tentacles.
Representatives of one recently open view octopuses behave even more unusually. The great Pacific striped octopus has not yet been formally described by science, but it is already clear that its sexual habits differ sharply from the behavior of other cephalopods.
This is one of the few social active species octopuses. They can live in groups, even in limited space, and do not maim or eat their fellow creatures.
This tolerance also extends to marriage rituals. "They copulate beak-to-beak, mouth-to-mouth," says Ross, who has observed it many times. This is quite strange, because a strong and sharp beak is the most dangerous weapon of a cephalopod.
In this unusual position, the pair of octopuses extend their tentacles together and their suckers appear to be touching each other. “It’s a very, very strange phenomenon,” Ross says, perplexed.
The greater Pacific striped octopus has a relative, the lesser Pacific striped octopus. These mollusks behave more typically. “The male jumps onto the female’s mantle from above, away from her tentacles,” says the scientist. “He does this surprisingly quickly, in case she has Bad mood. Then they mate and he swims away as quickly as possible."
The small Pacific striped octopus prefers not to take risks when mating
We don't know why great Pacific striped octopuses are so much more social than other cephalopods. The unusual nature of their behavior makes us remember that we generally do not understand the mating habits of octopuses very well. Why do such voracious, solitary creatures mate in such intimate positions?
Perhaps, despite sexual cannibalism, not too many octopuses die in the fatal tentacles of their partners, and a sufficient number of them manage to transfer sperm to the females. In this case, perhaps evolution does not push males to invent more safe ways sex.
“No one has figured it all out yet,” admits Mather. Perhaps because humans have so far studied only a few species. "We are in general outline imagine copulation in about a dozen shallow-water octopus species, says Huffard. “That means there are still 275 shallow-sea species left, all of them deep-sea.” These deep-sea dwellers can perhaps give us some idea of what octopus sex looked like at the dawn of evolution.
It will probably be a long time before we reach we'll understand in the end sexual behavior of octopuses. One of the problems is that they are very difficult to study. For starters, they live underwater and are skilled at camouflage. Well, when they meet, the researcher has to monitor 16 tentacles at once. "It's very difficult to see what's really going on there," Ross concludes.
Katherine Harmon Carege
How octopuses reproduce September 23rd, 2016
photo
Scientists have long established that almost all cephalopods, except for Nautilus and Argonauta octopuses, the only modern genus living in open seas, mate and reproduce once in a lifetime. After the offensive reproductive age octopuses begin to look for a partner, and until this moment they prefer to live separately from their relatives.
So how do octopuses reproduce?
In adult males, by this time, “packets” with sperm develop in the mantle cavity (in cephalopods they are called spermatophores), which are carried out through the funnel during the breeding season, along with streams of water. During mating, the male holds the female with his tentacle hand, and uses a special genital tentacle to introduce spermatophores into the mantle cavity of the female.
Researchers have noticed very Interesting Facts octopus breeding. Namely, during reproduction, males of some species try to mate with any representative of their genus, regardless of gender and age. Of course, in this case the eggs will not be fertilized, and the mating process itself is not as long as with a female of the appropriate age. For example, blue-ringed octopus Mating continues until the female gets tired and she forcibly tears the overexcited male away from her.
Mating occurs even more unusual in Argonaut octopuses.
They have well developed sexual dimorphism. Females are larger than males. They have a single-chamber shell, which is why they are sometimes confused with nautiluses, and the male does not have such a shell, but has a sexual tentacle called a hectocotylus. It develops in a special pouch between the fourth and second hands on the left side. The female uses the shell as a brood chamber, where she lays fertilized eggs.
Some people describe it like this: " The males of this species are not destined to experience satisfaction. This is because nature has endowed them with a very strange penis. After the octopus produces a sufficient amount of seminal fluid, the organ miraculously separates from the body and swims off into the depths of the sea in search of a suitable female Argonaut octopus. The ex-owner can only watch how he reproductive organ carries out mating with the “beautiful half”. Nature didn't stop there. And she made this process closed. After some time, the penis grows back. The rest is not hard to guess. And you say there are no long distance relationships :)"
But it's still a tentacle. In an adult male, the tentacle separates from the body when meeting a female, and this tentacle worm independently penetrates into her mantle cavity, where the spermatophores burst and the liquid from them fertilizes the eggs.
Most species of octopus lay their eggs at night, one at a time. For spawning, some females choose cavities or burrows in rocks, gluing the eggs to the ceiling or walls, while others prefer to carry a cluster of eggs glued together with them. But both of them continuously check and protect their eggs until the offspring appear.
The duration of egg development during octopus reproduction varies, on average up to 4-6 months, but sometimes it can reach a year, and in rare cases several years. All this time, the female octopus incubates the eggs, does not hunt or eat. Studies have shown that before reproduction, octopuses undergo a restructuring of the body; shortly before spawning, they stop producing the enzymes necessary for digesting food. Soon after the juveniles emerge from the eggs, the female dies, and the newborn octopuses are able to take care of themselves.
Although reports periodically appear about the possibility of repeated spawning in nature in some octopuses, this has not yet been documented. However, when keeping the octopus in home aquarium, Panamanian zoologist A. Rodanice managed to obtain offspring twice from females of the small Pacific octopus (Octopus chierchiae), on the basis of which he concluded that among the octopuses that are found off the coast of the Gulf of Panama, one or even three species are capable of mating and reproducing repeatedly.
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During reproduction, male cephalopods use one of their tentacles to remove spermatophores from the “sinus” (from the mantle cavity) and transfer them to the mantle cavity of the female. But Argonaut octopuses act differently. Their tentacle independently, without the help of a male, performs these duties. Having captured a pair of spermatophores, it breaks away and swims off in search of a female, like a remote-controlled torpedo.
“When the Argonaut offers his “hand” to a lady of his tribe, she accepts it and keeps it, taking it with her, and the gentleman’s hand becomes a mobile creature, living its own life for some time after it has come into the possession of the lady” - so somewhat pompous, but Henry Lee, the first naturalist who managed to find popular words to describe the most intimate aspects of the life of octopuses, put it quite decently.
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