How a white shark gives birth. How is a shark born? Shark Reproduction: Ovoviviparity
The sexual life of sharks has been studied rather poorly - after all, observing them is dangerous to health, and technically difficult.
Pioneers of sex
It was previously believed that sharks were the ones who invented sexual intercourse: researchers assumed that they were the first animals to join, ahem, genitals to exchange genetic material. All other animals, and especially plants, reproduced either with the help of external fertilization, or without it at all - by division.
However, a couple of years ago it was proven that armored fish, which appeared before sharks, also had sex, so the palm went to them.
On the other hand, those fish became extinct long ago, but sharks still exist, so we can say that of all the organisms living on earth, they have the greatest sexual experience. During research work in Western Australia several years ago, they even found the fossilized remains of giant prehistoric fish from a genus of extinct sharks of the Cretaceous period, depicted in a very ambiguous pose.
The ancestors of modern predators were pressed tightly against each other with their bellies and clearly did not expect that sudden death would overtake them at the most inopportune moment. By the way, some species of these fish can be called not pioneers, but retirees of sex - female Greenland polar sharks living in the waters of the North Atlantic reach puberty at the age of about 150 years! However, to be fair, it is worth noting that they live two or even three times longer.
Victims of violence
Can you tell on the subway in the morning which of those around you had sex last night? And those who last did this a month or two ago? How about six months? If you are not a psychic - which does not exist - then the result is predictable.
But if we are talking about sharks, then the traces of a stormy night are immediately visible, and this is not at all a satisfied smile from the full toothy mouth - biologists can count the number of sexual intercourses a shark has by the scars on its body. The fact is that in most species of sharks there is an equal sign between sex and violence: the male literally brutally rapes the female, pouncing on her and holding her fins with his teeth. The female tries to fight back, so the gentleman also gets the worst of it.
Violence often occurs in groups: during the breeding season, males gather in schools and hunt females, who try to hide from them in shallow water. However, the male shark does not impregnate everyone; he can choose “the one” for quite a long time in order to pursue her for a long time and persistently.
Not only carnivorous species behave this way: for example, giant sharks, which feed on plankton and won’t hurt a fly, behave just as barbarically: scientists even believe that huge teeth, which are not used either for hunting or for digestion, were left just for sexual needs.
Missionary position
Despite the fact that sharks are pioneers of sex, nature has never come up with anything better than the missionary position for them: the female and the male mate in the most classic position. Moreover, this is a prerequisite for sex, otherwise nothing will work out. When a male attacks a female, his task is to turn the lady onto her back at all costs, who fights back with all her might, using sharp teeth.
If the attempt to place the female on her shoulder blades is crowned with success, the job is done - she will fall into a state of tonic immobility, something between a trance and a coma. True, a shark needs to move in order to breathe, and in a coma it cannot do this, so more than 15 minutes of trance are fraught with death.
By the way, there are known cases when killer whales put sharks into a state of tonic immobility - not for sex, but just to have lunch.
No man? And it is not necessary
When sex turns from pleasure into torture, and you have to reproduce somehow, willy-nilly you have to look for other ways. And nature has found them for sharks: there are known cases where fertilization occurred in females without the participation of a male. True, in fact, the reason is not fear of violence, but long-term abstinence - parthenogenesis usually occurred in captivity, in aquariums, where females were kept alone for a long time.
This is believed to be a defense mechanism that prevents sharks from becoming extinct. These ancient predators also have another useful trick: they know how to store their partner’s sperm for several years and use it only at a favorable moment for themselves. Moreover, even if a shark is impregnated by several males, it will give birth to offspring from “that one” (although scientists just a few years ago put forward the theory that under such conditions, if several sharks are born, they may be from different fathers). The only thing that still remains a mystery is the mechanism for selecting the genetic material of a particular lover.
Eat your brother
Severe fish have harsh morals: many aquatic predators eat both their own offspring and smaller relatives that accidentally turn up along the way. But sharks have gone the furthest: they are the only ones who practice fetal cannibalism. It is characteristic of ovoviviparous species that do not lay eggs in the sand, but carry them in utero.
At a certain stage, the embryo leaves the egg, and failed brothers and sisters who have not yet hatched become food for it. Is it any wonder that a shark is born a full-fledged predator, ready to tear and throw - unless he devours his own mother, of course.
To be fair, this rarely happens: nature turns on a protective mechanism, thanks to which the female after childbirth completely loses her appetite.
Representatives of the superorder Sharkidae reproduce offspring in several ways, depending on their biological species. Characteristic feature shark breeding is internal fertilization.
This is how they differ from most other fish. For this purpose, males have a special reproductive organ - a pterygopodium. Juveniles can be born from eggs or through ovoviviparity. Also, in some varieties, true viviparity occurs.
About a third of all these marine predators reproduce by eggs or capsules. They are covered on top with a dense horny shell, unlike bird shells, and may not have a round, but an intricate shape. They may have outgrowths or antennae, with the help of which they linger at the bottom among algae or stones.
Inside the capsules there is a large amount of nutrients, due to which the embryo grows and develops. The incubation period can be long, sometimes lasting more than a year. After its completion, a fully formed fry is born, which is capable of obtaining food as an adult animal.
This is how most benthic species reproduce, laying no more than 15 eggs at a time. Of the free-swimming species, the polar variety is known, which lays up to 500 capsules.
Shark breeding: ovoviviparity
This method differs from true viviparity in that the fertilized eggs remain to develop in the female's body. When the fry are already sufficiently formed and developed, the female gives birth to fully formed live fry. But the juveniles receive nutrients not from the mother’s body, but from the capsule in which they are located.
Ovoviviparity allows you to save offspring much more effectively than with oviparity. The deposited capsules can become easy prey for predators, but when they are in the female’s body, they are reliably protected during their development.
Cases of parthenogenesis, or asexual reproduction, have also been documented in these animals. In the absence of a male, the female is sometimes able to reproduce without fertilization.
This amazing feature allows these inhabitants of the sea to give birth to offspring in any conditions, and protects these fish from extinction.
Many species reproduce by ovoviviparity, for example, tiger and katran, which produce up to 50 fry in a litter.
True live birth
This method is similar to the reproduction of mammals, when the embryo is located in a special organ - the uterus, and is connected to the mother’s body through the placenta. The placenta appears over time. Until this moment, the embryo develops due to its yolk sac.
Shark breeding, in which live babies are born, is considered the most progressive method. This method is found only in cartilaginous fish and is not typical for bony fish.
Such reproduction of their own kind is observed not only in the most modern species, but also occurs in the most ancient ones. About one tenth of all these ocean predators living today reproduces in this way.
Viviparity as a method shark breeding is a progressive step on the evolutionary path of these species. At the same time, fully formed cubs appear, the survival rate of which is much higher than that of the larvae emerging from the eggs.
Therefore, if egg-laying fish can lay several hundred eggs, of which only a few survive to adulthood, then viviparous fish only need to give birth to several young to ensure the survival of the species.
The sexual life of sharks has been studied rather poorly - after all, observing them is dangerous to health, and technically difficult.
Pioneers of sex
It was previously believed that sharks were the ones who invented sexual intercourse: researchers assumed that they were the first animals to join, ahem, genitals to exchange genetic material. All other animals, and especially plants, reproduced either with the help of external fertilization, or without it at all - by division.
However, a couple of years ago it was proven that armored fish, which appeared before sharks, also had sex, so the palm went to them.
On the other hand, those fish became extinct long ago, but sharks still exist, so we can say that of all the organisms living on earth, they have the greatest sexual experience. During research work in Western Australia several years ago, they even found the fossilized remains of giant prehistoric fish from a genus of extinct sharks of the Cretaceous period, depicted in a very ambiguous pose.
The ancestors of modern predators were pressed tightly against each other with their bellies and clearly did not expect that sudden death would overtake them at the most inopportune moment. By the way, some species of these fish can be called not pioneers, but retirees of sex - female Greenland polar sharks living in the waters of the North Atlantic reach puberty at the age of about 150 years! However, to be fair, it is worth noting that they live two or even three times longer.
Victims of violence
Can you tell on the subway in the morning which of those around you had sex last night? And those who last did this a month or two ago? How about six months? If you are not a psychic - which does not exist - then the result is predictable.
But if we are talking about sharks, then the traces of a stormy night are immediately visible, and this is not at all a satisfied smile from the full toothy mouth - biologists can count the number of sexual intercourses a shark has by the scars on its body. The fact is that in most species of sharks there is an equal sign between sex and violence: the male literally brutally rapes the female, pouncing on her and holding her fins with his teeth. The female tries to fight back, so the gentleman also gets the worst of it.
Violence often occurs in groups: during the breeding season, males gather in schools and hunt females, who try to hide from them in shallow water. However, the male shark does not impregnate everyone; he can choose “the one” for quite a long time in order to pursue her for a long time and persistently.
Not only carnivorous species behave this way: for example, giant sharks, which feed on plankton and won’t hurt a fly, behave just as barbarically: scientists even believe that huge teeth, which are not used either for hunting or for digestion, were left just for sexual needs.
Missionary position
Despite the fact that sharks are pioneers of sex, nature has never come up with anything better than the missionary position for them: the female and the male mate in the most classic position. Moreover, this is a prerequisite for sex, otherwise nothing will work out. When a male attacks a female, his task is to turn the lady onto her back at all costs, who fights back with all her might, using sharp teeth.
If the attempt to place the female on her shoulder blades is crowned with success, the job is done - she will fall into a state of tonic immobility, something between a trance and a coma. True, a shark needs to move in order to breathe, and in a coma it cannot do this, so more than 15 minutes of trance are fraught with death.
By the way, there are known cases when killer whales put sharks into a state of tonic immobility - not for sex, but just to have lunch.
No man? And it is not necessary
When sex turns from pleasure into torture, and you have to reproduce somehow, willy-nilly you have to look for other ways. And nature has found them for sharks: there are known cases where fertilization occurred in females without the participation of a male. True, in fact, the reason is not fear of violence, but long-term abstinence - parthenogenesis usually occurred in captivity, in aquariums, where females were kept alone for a long time.
This is believed to be a defense mechanism that prevents sharks from becoming extinct. These ancient predators also have another useful trick: they know how to store their partner’s sperm for several years and use it only at a favorable moment for themselves. Moreover, even if a shark is impregnated by several males, it will give birth to offspring from “that one” (although scientists just a few years ago put forward the theory that under such conditions, if several sharks are born, they may be from different fathers). The only thing that still remains a mystery is the mechanism for selecting the genetic material of a particular lover.
Eat your brother
Severe fish have harsh morals: many aquatic predators eat both their own offspring and smaller relatives that accidentally turn up along the way. But sharks have gone the furthest: they are the only ones who practice fetal cannibalism. It is characteristic of ovoviviparous species that do not lay eggs in the sand, but carry them in utero.
At a certain stage, the embryo leaves the egg, and failed brothers and sisters who have not yet hatched become food for it. Is it any wonder that a shark is born a full-fledged predator, ready to tear and throw - unless he devours his own mother, of course.
To be fair, this rarely happens: nature turns on a protective mechanism, thanks to which the female after childbirth completely loses her appetite.
What is the difference between viviparity and ovoviviparity?
In placental viviparity, the fetus receives oxygen and nutrients from the mother's blood with the help of special organs - the placenta and umbilical cord. This is typical for all mammals except oviparous mammals - the platypus and echidna.
Viviparity in sharks is the only example of placental viviparity in cold-blooded vertebrates.
In ovoviviparity, eggs develop in the female's genital tract, but there is no direct contact and exchange of substances between the organisms of the mother and fetus. The cubs hatch from the egg shell in the posterior part of the mother's oviduct, and only after this they are born.
During their development, they feed mainly on the nutrients of the yolk sac. In sharks, feeding such embryos is possible in several other very specific ways (oophagy and the formation of royal jelly).
In addition to sharks, ovoviviparity is typical for species of lizards and snakes living in colder climates, some bony fish (swordtails, guppies, molynesias, gambusias), and certain species of toads. Reptiles do not have any additional devices for feeding; their embryos, during ovoviviparity, receive only water from the female genital tract.
Watch video - Embryonic oophagy in sharks:
Who discovered viviparity in sharks?
Viviparity in sharks was first identified by the ancient Greek scientist and philosopher Aristotle. He could distinguish the egg capsules of viviparous and oviparous sharks by their appearance. Viviparous sharks produce eggs with translucent shells.
The 16th century French physician and zoologist Rondelet, in his book about ocean fish posted a drawing of a female shark connected by an umbilical cord to her baby. But the whole process was studied in most detail by the German zoologist Muller.
What are the features of viviparity in sharks?
At the beginning of development, embryos use the yolk, rich in high-calorie lecithin. Then part of the thin capsule of the egg and the wall of the already empty yolk sac form folds that tightly fit into the depressions in the wall of the uterus. Due to the formed folds, the surface area of contact between the organisms of the mother and the calf increases. This complex complex is called the placenta.
Through the placenta, all the substances necessary for growth and development enter the blood of the fetus: amino acids for the synthesis of proteins, sugars and fats as sources of energy and building material for cells.
IN reverse direction Toxic metabolic products pass into the female’s blood: ammonia, urea, carbon dioxide. A fairly long umbilical cord stretches from the placenta to the embryo, through the blood vessels of which blood moves in both directions.
What types of sharks are viviparous?
Placental viviparity occurs in 9% of all shark species: some hammerheads, some mustelids, and most carcharine sharks.
The American mustel shark gives birth to 10 to 20 young. The Cuban mustel shark, 30-40 cm long, usually develops 2 embryos in the uterus.
The longtip shark from the family of gray sharks gives birth to 5 to 7 sharks about 40 cm long.
Among hammerhead sharks, only some species have placental viviparity. Viviparous have 6 to 9 young, and ovoviviparous have 30-40, but all of them are born with the same proportions as adults and up to 50 cm in size.
Watch video - Embryo of a viviparous shark:
Which sharks are ovoviviparous?
This is the most “popular” method of reproduction among sharks, because this is how 48% of cartilaginous fish reproduce. Of these, 27% feed only from the yolk sac, 2% from embryophagy and oophagy (embryonic cannibalism), and 19% from royal milk (the so-called royal viviparity).
Watch video - Embryo of an ovoviviparous shark:
It turns out that many sharks bear young in the same way as mammals and humans. This means that in their biology they are not so far from us.
Is this why people of a certain character are called “sharks”?
How is a shark born?
Aren't all animals born alive? There can be no doubt about this obvious fact, but birth cannot always be called a live birth. In animals, there are 3 types of individual development of the organism, or ontogenesis - larval, oviparous and intrauterine.
Most bony fish have a larval type, but sharks are characterized by oviparity and intrauterine birth, that is, viviparity. In many species, development is something between oviparous and intrauterine development - ovoviviparity.
What is the difference between viviparity and ovoviviparity?
In placental viviparity, the fetus receives oxygen and nutrients from the mother's blood with the help of special organs - the placenta and umbilical cord. This is typical for all mammals except oviparous mammals - the platypus and echidna.
Viviparity in sharks is the only example of placental viviparity in cold-blooded vertebrates.
In ovoviviparity, eggs develop in the female's genital tract, but there is no direct contact and exchange of substances between the organisms of the mother and fetus. The cubs hatch from the egg shell in the posterior part of the mother's oviduct, and only after this they are born.
During their development, they feed mainly on the nutrients of the yolk sac. In sharks, feeding such embryos is possible in several other very specific ways (oophagy and formation).
In addition to sharks, ovoviviparity is typical for species of lizards and snakes living in colder climates, some bony fish (swordtails, guppies, molynesias, gambusias), and certain species of toads. Reptiles do not have any additional devices for feeding; their embryos, during ovoviviparity, receive only water from the female genital tract.
Watch video - Embryonic oophagy in sharks:
Who discovered viviparity in sharks?
Viviparity in sharks was first identified by the ancient Greek scientist and philosopher Aristotle. He could distinguish between the egg capsules of viviparous and oviparous sharks by their appearance. Viviparous sharks produce eggs with translucent shells.
The 16th century French physician and zoologist Rondelet, in his book on ocean fish, included a drawing of a female shark connected by an umbilical cord to her baby. But the whole process was studied in most detail by the German zoologist Muller.
What are the features of viviparity in sharks?
At the beginning of development, embryos use the yolk, rich in high-calorie lecithin. Then part of the thin capsule of the egg and the wall of the already empty yolk sac form folds that tightly fit into the depressions in the wall of the uterus. Due to the formed folds, the surface area of contact between the organisms of the mother and the calf increases. This complex complex is called.
Through the placenta, all the substances necessary for growth and development enter the blood of the fetus: amino acids for the synthesis of proteins, sugars and fats as sources of energy and building material for cells.
In the opposite direction, toxic metabolic products pass into the female’s blood: ammonia, urea, carbon dioxide. A fairly long umbilical cord stretches from the placenta to the embryo, through the blood vessels of which blood moves in both directions.
What types of sharks are viviparous?
Placental viviparity in 9% of: some hammerheads, some mustelids, and most carcharines (grays).
The American mustel shark gives birth to 10 to 20 young. The Cuban mustel shark, 30-40 cm long, usually develops 2 embryos in the uterus.
From the family of gray sharks, it brings from 5 to 7 sharks about 40 cm long.
Among placental viviparity, only some species have placental viviparity. Viviparous have 6 to 9 young, and ovoviviparous have 30-40, but all of them are born with the same proportions as adults and up to 50 cm in size.
Watch video - Embryo of a viviparous shark:
Which sharks are ovoviviparous?
This is the most “popular” method of reproduction among sharks, because this is how 48% of cartilaginous fish reproduce. Of these, 27% feed only from the yolk sac, 2% from embryophagy and oophagy (), and 19% from royal milk (the so-called royal viviparity).
Watch video - Embryo of an ovoviviparous shark:
It turns out that many sharks bear young in the same way as mammals and humans. This means that in their biology they are not so far from us.
Is this why people of a certain character are called “sharks”?
Greetings, shark lovers and non-shark lovers!
By the way, check in the comments who is more here - those who love sharks or those who don’t like them?
Today's question is: How do sharks reproduce? As always, immediate response.
Sharks reproduce through internal fertilization. The male swims up to the female, first sticks his sharp teeth into her to hold her with his jaws near him, and then the pterygopodia genitals. And after mating, as is usually typical of males, it runs away from the scene. After 1-2 years, the shark gives birth to children (from the egg or from the womb - depending on the type of predator).
Pay attention to an interesting feature - the male shark has 2 genitals! During sex, he only uses one of them. Why do you think nature gave the shark two genital organs? Write your opinions in the comments!
In general, the process of reproduction in sharks is accompanied by incredible cruelty - these are the only creatures on the planet in which the creation of offspring occurs in unimaginably dangerous conditions.
First, the male torments the female with powerful jaws like a hot water bottle, leaving serious injuries on her body (wow, hickeys), and then, already in the womb, deadly battles of embryos take place - unborn sharks in the stage of embryonic development attack each other and devour the weaker ones.
It is in such conditions that the legendary predators No. 1 appear, emerging into the world with scars and with blood on their lips instead of milk.
Is this why people are so concerned about how sharks reproduce?
And here is a video on the topic of shark reproduction, after watching which it becomes clear that the toughest and most extreme sex is with these predators
Can you guess why there is no pose called Shark in the Kama Sutra?
By the way, from the video it becomes clear why sharks do not suffocate while lying on the bottom in a state of ecstasy. After all, it is known that they do not have gill covers and they must always swim to pass water through their gills to obtain oxygen.
Guys, what would happen if people reproduced the same way sharks reproduce? Write your versions in the comments - it will be fun to read your opinions!
But in this video you can see how whitetip reef sharks reproduce
True, the video looks more like filming group shark pornography than the reproduction of two sharks.
But this video shows bloody battles of embryos - for impressionable and pregnant women, please DO NOT WATCH!
Now do you understand how sharks reproduce? Cruel and merciless!
Why do you think nature chose such a difficult path for sharks in reproduction and production of offspring? After all, there are many dangerous predators in the world. But the way sharks reproduce does not happen to any creature on the planet.
And here's another terrible video on the topic of shark reproduction - here a researcher looked inside the womb of a sand tiger shark (and probably stopped wanting to have children)
Do sharks reproduce by eggs or are they viviparous?
About 30% of sharks reproduce by eggs (oviparous), about 10% of sharks are viviparous, and all the rest are ovoviviparous (babies are born from eggs inside the mother's womb).
The reproductive process of sharks is not only dangerous, but also quite long: incubation of eggs can last more than 1 year, and the gestation period during live birth in sharks ranges from 10 months to 2 years.
In this video you can see a newly laid egg from a shark that reproduces with eggs.
This video shows the birth of a baby
Check out this video! Who wants the same keychain?
And this is how sharks reproduce by viviparity - in the video there is a lemon shark
Write in the comments which sharks would you be interested in seeing reproduce? Personally, I would look at how sawnose sharks reproduce - with such a saw, this is probably very problematic. Surely nature has provided something for this case of reproduction as well.
For the same reason, it would be interesting to watch the hammerhead shark.
And now I propose to speculate a little about how the most famous species of sharks reproduce.
How does a white shark reproduce?
The white shark reproduces by ovoviviparity. The eggs are formed in the mother's womb, and the fry hatch from them there. There is no placental connection with the maternal body.
The strongest cubs eat the weak ones while still inside. 2-3 independent baby sharks are born, ready to hunt. The length of a born white shark baby is 1.2-1.5 meters.
Many people would like to watch great white sharks mate. Imagine two giant monsters who have just bitten a couple of bathers in half, and after a hearty lunch merged in ecstasy.
There are still no photographs or videos of this process. Scientists are content only with footage of females who have been in the arms of deadly gentlemen:
There is also not a single video of the birth of a white shark in its natural habitat.
White sharks reproduce very slowly due to their long time to reach maturity. Pregnancy lasts more than 1 year.
By the way, does anyone know why white sharks swim to a certain place in the World Ocean to reproduce (), and not mate like reef sharks?
Due to the long period of reaching sexual maturity and low fertility, white sharks are on the verge of extinction - their numbers are steadily declining.
There is an established opinion on the Internet that no more than 4,500 individuals of white sharks live in the world’s oceans.
I believe that this information has long been outdated, like the stupid phrase “Currently, about 360 species of sharks are known,” which can still be found on resources that have not been updated for a long time (now, probably, the number of shark species has exceeded 600 ).
In my opinion, the number of white sharks in the world's oceans is still gradually growing. Scientists' data are based only on manual counting of the number of individuals. Somewhere on this site I saw information about recent studies in which scientists carried out simulations with quite high percentage reliability. According to calculations, the number of white sharks in the world's oceans can reach 70 thousand individuals.
So all is not lost - let's hope that the coolest and most ancient predators of our planet - great white sharks - will survive and continue to excite the heads of humanity!
How do tiger sharks reproduce?
Tiger sharks belong to the family Carcharhinidae (gray sharks, or carcharine sharks). All carcharine sharks are placental, with the exception of the tiger shark.
This species of predator once had a placenta, which was later lost during evolution. Tiger shark in large quantities produces energy-rich nutrients (uterine fluid) in the uterus for the formation of fertilized eggs and the rapid growth of embryos so that they can actively gain weight.
A detailed study on the reproduction of tiger sharks can be read in the article
And here you can see what baby tiger sharks look like straight from the womb: Rescue of unborn tiger sharks in Taiwan
How does a whale shark reproduce?
About reproduction whale shark There is practically no information despite the fact that this large species of predator has been studied for more than 100 years.
According to one version of scientists, the whale shark reproduces by ovoviviparity. Up to 40 embryos can develop in the reproductive tract at the same time. The female stores the male's sperm for some time, since it is unknown when the next meeting will take place. Pregnancy lasts approximately two years.
The embryos develop in capsule eggs, hatching from them in the womb, although previously scientists assumed that this fish lays eggs. Whale shark eggs and embryos were only discovered in the 20th century.
In 1910, a female whale shark caught off Ceylon had 16 egg capsules in her oviducts.
In 1955, a similar capsule was discovered off Texas at a depth of 57 meters. It contained a whale shark embryo. The egg was 63 cm long and 40 cm wide.
Off the coast of Japan, a female whale shark was once caught with a baby shark in her oviduct that had not yet hatched. The birth was successfully delivered, and the newborn was placed in an aquarium, where he refused food for more than two weeks (newborns are supplied with a supply of nutrients in a special yolk sac). Only after 17 days they began to gradually feed him with zooplankton.
Russian Research Institute fisheries and oceanography, the only one in the world can boast that among the exhibits of its museum is a stuffed newborn baby whale shark 59 cm long.
Keeping in mind the size of an adult whale shark (15 meters in length and weighing about 20 tons), the size of the eggs will surprise few people - 60 cm in length and 40 cm in width.
But the shape... A rectangle with four long strong tendrils at the corners. It’s just any farmer’s dream - it’s easy to transport and doesn’t roll off the table.
These sealed capsules are very rare.
Check out this giant whale shark's egg! Do they remind you of anything? 
Fun facts about how sharks reproduce. Let's sum it up
1. Pioneers of sex
Sharks invented sexual intercourse: they are the only living creatures on the planet that joined, ahem, genitals to exchange genetic material. All other animals, and especially plants, reproduced either with the help of external fertilization, or without it at all - by division.
Thus, sharks have the most sexual experience on Earth!
During research work in Western Australia, they even found the fossilized remains of giant prehistoric fish from a genus of extinct sharks of the Cretaceous period, captured in a piquant pose. Apparently, the sedimentary rocks that covered the predators during sex were also interested in how sharks reproduce.
By the way, some species of sharks can be called not pioneers, but retirees of sex: female Greenland sharks living in the waters of the North Atlantic reach puberty at the age of about 150 years! And their lifespan can reach up to 500 years! This is one of the longest living animals on the planet
2. Victims of violence
Can you tell on the subway in the morning which of those around you had sex last night? And those who last did this a month or two ago? How about six months? If you are not a psychic, then no.
But if we are talking about sharks, then the traces of a stormy night are immediately visible, and this is not at all a satisfied smile from the full toothed mouth - biologists can count the number of sexual intercourses a shark has by the scars on its body. ABOVE I provided a video telling how sharks reproduce.
The fact is that in most species of sharks there is an equal sign between sex and violence: the male literally brutally rapes the female during reproduction, pouncing on her and holding her fins with his teeth. The female tries to fight back, so the gentleman also gets the worst of it.
Violence often occurs in groups: during the breeding season, males gather in schools and hunt females, who try to hide from them in shallow water. However, the male shark does not impregnate everyone; he can choose the one for quite a long time in order to pursue her for a long time and persistently.
How do sharks that feed on plankton reproduce? They wouldn't hurt a fly, would they? Yes, yes, they behave just as barbarically: some scientists even believe that a large number of teeth (about 10 thousand in a whale) are not used for hunting or for digestion, but are needed specifically for sexual needs!
What do you think - how exactly do huge planktivorous sharks have sex? Write your opinions in the comments!
3. Missionary position
Despite the fact that sharks are pioneers of sex, nature has never come up with anything better than the missionary position for them: the female and male reproduce in the most classic position.
Moreover, this is a prerequisite for sex, otherwise nothing will work out. When a male attacks a female, his task is to turn his girlfriend onto her back at all costs, who fights back with all her might, using her sharp teeth.
If the attempt to place the female on her back is successful, the job is done - she will fall into a state of tonic immobility, something between a trance and a coma. True, a shark needs to move in order to breathe, and in a coma it cannot do this, so more than 15 minutes of trance are fraught with death.
By the way, information about how sharks reproduce is also used by killer whales - they also turn sharks onto their backs. True, not for sex, but just to have lunch.
4. No man? And it is not necessary
But this is the coolest feature on the topic - how sharks reproduce! When sex turns from pleasure into torture, and you have to reproduce somehow, willy-nilly you have to look for other ways. And nature has found them for sharks: there are known cases where fertilization occurred in females without the participation of a male.
True, in fact, the reason is not fear of violence, but long-term abstinence - parthenogenesis usually occurred in captivity, in aquariums, where females were kept alone for a long time. This is believed to be a defense mechanism that prevents sharks from becoming extinct.
Another one interesting feature reproduction of sharks - they know how to store their partner’s sperm for several years and use it only at a favorable moment for themselves. Moreover, even if a shark is impregnated by several males, it will produce offspring from that one. The mechanism for selecting the genetic material of the desired lover still remains a mystery.
5. Eat your brother
Many aquatic predators eat both their own offspring and smaller relatives that accidentally turn up along the way. But sharks have gone the furthest in matters of reproduction: they are the only ones who practice embryonic cannibalism. It is characteristic of ovoviviparous species that do not lay eggs, but carry them in utero.
At a certain stage of development, the embryo in the mother’s womb leaves the egg and its brothers and sisters become food for it.
On this cheerful note, we can close the topic of how sharks reproduce.
Friends, tell us in the comments what else I missed about shark reproduction? Share your impressions of what you read and saw in the video!
A shark is a fish that is an absolute predator. It serves as a kind of regulator not only of the number of inhabitants of the deep sea, but also as a nurse, since its victims, as a rule, are weak or sick individuals. In addition, it is the shark that serves as a stimulant for the improvement and self-development of those it eats. After all, wanting to protect themselves from predators, the inhabitants of the seas and oceans strive to improve their camouflage qualities, learn to develop greater speed of movement, that is, they evolve. And in order to regulate the shark population and preserve the population of its potential victims, nature has provided for the reproduction activity of both. And the shark is far from being in first place in this ranking - it reproduces much more slowly than other fish.How do sharks reproduce?
Sharks belong to the type of skeletal structure of cartilaginous fish and reproduce, like their relatives, using the so-called internal fertilization, in which the reproductive products of the male are introduced into the body of the female and embryos are conceived there.According to the type of birth of offspring, sharks are divided into three main types - oviparous, ovoviviparous and viviparous. Oviparous sharks simultaneously produce from 2 to 12 eggs, which they hang in small groups on algae. The shells of eggs are very strong and reliably protect the young from mechanical damage and attacks from other predators.
In ovoviviparous sharks, egg development and shell rupture occur in utero. After “birth,” the offspring remain inside the mother for some time, and are released into the world as almost fully formed individuals, capable of independent, full-fledged existence.
In viviparous female sharks, conception, growth and development of embryos occurs without the formation of a shell. This method of reproduction corresponds to the highest type of organisms inhabiting planet Earth. Viviparous sharks account for more than 10% of all shark species, and they give birth to 3 to 15 young at a time.
Shark eggs often have a very unusual shape and are called "mermaid's purse". Oceanologists found a clutch in which all the eggs were placed in a shell resembling a bag, the cavity of which was filled with collagen mass.
One shark egg can contain several embryos at the same time, but only one of them, the strongest, survives. Moreover, in the process of its development inside the egg, it eats its weaker brothers.
The size of a shark egg ranges from the size of a goose egg or a human palm to elongated spheres up to 2 meters long.
