Who would have thought that fish are such amazing creatures that they live much longer than humans? At the beginning of August, we wrote that a 112-year-old fish that survived two World Wars was found in the waters of the American state of South Dakota. Scientists called it the oldest fish in the world, but it seems they were very wrong. A huge shark was caught in the waters of Greenland, which, according to scientists, was born back in 1505. It turns out that she swam in cold waters back in the time of Ivan the Terrible?
The lifespan of fish is truly amazing. It is known that in the wild, salmon can live up to 15 years, and sturgeon can swim calmly until they reach 100 years of age. But these are just flowers - there is a legend that in 1794 Moscow fishermen managed to catch a pike that lived during the reign of Boris Godunov, that is, more than 200 years ago. But compared to the shark caught in Greenland, even this legendary fish seems like a teenager.
Lifestyle
Who are sharks? They first appeared 450 million years ago. Since that time, these creatures have hardly changed. A shark is a fish that lived in the oceans long before dinosaurs.
There are about 450 species of sharks on the planet. These cartilaginous fish differ greatly from each other. The largest of them reaches a length of 20 m, while the length of the smallest is only 17 cm. Some of these predators, inhabitants of the depths, are able to glow with the help of special organs, luring prey.
How many years do sharks live? The answer to this question will be individual for each specific species. Polars are true long-livers. The lifespan of a shark of this species is more than 100 years. The life of a whale lasts more than 70 years. How long do these predators live on average? Most species have a lifespan ranging from 20 to 30 years.
The life of sharks is subject to a complex hierarchy that operates not only within one species, but also between representatives of different species. A significant number of species of these fish coexist with each other in large groups.
They swim at low speed most of the time. The average speed of a shark ranges from 8 to 9 km/h. During a throw at a potential victim, they are capable of noticeably accelerating. The mako shark is considered the fastest. It is capable of reaching speeds of up to 50 km/h.
How long do sharks live? Detailed answer
From this article you will learn how long sharks live .
Sharks are one of the most interesting ocean representatives. They have inhabited the depths of the sea for more than five hundred (500) million years. Instant answer: There are currently about one hundred ( 100 ) species of sharks. Different representatives of these creatures differ in life expectancy. Long-lived sharks can live more than 80 years (for example, the whale shark).
Anatomical data
Different types of sharks differ from each other in appearance. The sizes of these animals can vary greatly. What do sharks look like? Fish have a streamlined body shape, a specially shaped caudal fin, as well as two dorsal fins, an anal fin, paired abdominal and pectoral fins, and many teeth growing in several rows. The closest relatives of these creatures are stingrays.
The structure of a shark is different from that of other fish. These predators belong to cartilaginous fish. The name refers to one feature of shark anatomy. Their skeleton consists not of bones, but of cartilage.
The scales of the predator are designed in such a way that the tips of the scales protrude outward from the skin. They fit very tightly to each other, due to which the shark’s skin can appear either smooth if you run your hand in the direction from head to tail, or hard, rough, resembling sandpaper, if you stroke the sea predator in the opposite direction.
The teeth of these predators grow in several rows; their structure varies among different species and depends on what the fish feeds on. If for some reason the shark loses a tooth, the one in the previous row will take its place. In the very last row, after a while a new one will grow. As long as this predator lives, its teeth grow. The structure of the dental apparatus can reveal a lot about sharks.
Katran Gini
Katran Gini has big blue eyes, like anime characters. (Image credit: MarAlliance)
The strangest sharks include the Genie, which has large blue eyes. These sharks (Squalus clarkae) are deep-sea creatures found in the Gulf of Mexico and the western Atlantic Ocean. They are small in size (50 to 70 cm) and their large blue eyes make them look like cute anime characters.
The shark species was discovered and officially described in 2022.
Physiology
How do sharks breathe? A shark is a fish, and its respiration occurs in the same way as in other chordates. For this purpose, a special organ is used - gills. A shark's gill sacs open inward into the throat and outward at the sides of the head. There can be from 5 to 7 pairs of gill slits. Cartilaginous fish use gills only for breathing.
Most of these marine predators are cold-blooded animals. Only a few species are classified as partially warm-blooded. These shark species have thermoregulation that is different from others. They are able to maintain a body temperature 9-13°C warmer than the surrounding water. However, such a temperature difference does not apply to the entire body of the predator. Near the gills and heart the temperature will be equal to the ambient temperature.
Since sharks do not have a swim bladder, they must constantly be on the move. The need to constantly swim is due to the fact that most of these fish are not able to pump water through their gills on their own. Shark hunters use this. If you pull a shark down by its tail for a while, no water will flow into its gills. In this case, the predator may drown. However, there are exceptions to this rule. One of them is the nurse shark, which is able to maintain the functioning of the respiratory system while lying on the bottom.
How does a shark compensate for negative buoyancy? Compensation occurs by reducing body weight. This is helped by the cartilaginous skeleton, which is much lighter than the bone one, as well as the accumulation of carbon in the liver. To make swimming easier, the skin is covered with a thin film of fat. Some predators create positive buoyancy in a different way. They swallow air, creating a makeshift swim bladder from their stomach.
Myth 6. Shark fins are very useful.
Shark fin soup.
Image: chee.hong / Wikimedia Commons A fairly popular misconception is that different parts of sharks - such as their fins or cartilage - can heal various diseases, especially cancer. And also prolong life, increase intelligence, improve potency and increase any body parts you want.
But this is also a myth. Despite what alternative medicine proponents may claim, shark cartilage powder or fin soup does not cure cancer. Here's what Sharks Do Get Cancer: Tumor Found in Great White / Live Science says about it, a shark researcher.
Even if sharks didn't get cancer, eating shark products wouldn't cure it. It's like eating Michael Jordan in hopes of becoming a basketball player.
David Shiffman
Oceanologist from the University of Miami.
Moreover, shark fins, which largely consist of the same cartilage tissue, have extremely low nutritional value. And eating them in general is unlikely to somehow improve your well-being.
In addition, scientists from the University of Miami identified N. Hammerschlag. Cyanobacterial Neurotoxin BMAA and Mercury in Sharks/Toxins that the fins of some sharks contain significant amounts of mercury and a neurotoxin called BMAA.
Pisces are fine, they don’t pay attention to such little things. But a person can get degenerative brain diseases, such as Alzheimer's, Parkinson's and Lou Gehrig's diseases, or amyotrophic lateral sclerosis. And problems with the reproductive system for starters.
Food and hunting
What do sharks eat? The answer to this question will be different for different species of marine predators. Sharks are all carnivores, but their food preferences differ. Because these marine animals expend a lot of energy by constantly moving, they need to consume large amounts of fatty foods.
Most species do not attack humans. Only rare predators pose a danger.
The tiger shark, which feeds on everything that comes its way, including inedible objects, has earned the title of marine scavenger.
The largest shark, the whale shark, eats plankton. During feeding, it swims very slowly, developing a speed of no more than 1 m/s. The teeth of this shark species are not designed for grasping flesh. They are needed to hold plankton in the mouth. This type of shark is safe for humans. In addition to the whale shark, there are 2 more species of sharks that feed on plankton.
The great white shark's main diet consists of fish, pinnipeds, dolphins and porpoises. In addition, this predator can also eat carrion. Man is not the usual food of creatures. They attack people by mistake.
The main product in the diet of many sharks is fish. Cases of cannibalism are common. For this reason, cubs often live away from adults.
How do these creatures get their food? The answer to this question depends on the type of food of a particular species. The largest creatures feed on zooplankton, which they catch in their wide-open mouths, swimming through concentrations of krill at low speeds. Some believe that these giants are sharks without teeth. They have teeth, but they are not intended for tearing meat out of the victim's body.
Small-sized creatures hunt schooling fish.
Larger species hunt larger prey. They often lie in wait for prey, swimming around it in circles, after which, waiting for the right moment, they make a sharp jerk, attacking the victim. At the moment of throwing, this fish develops a speed significantly higher than usual. Such throws take a lot of energy and strength. At what speed are these throws made? From 19 to 50 km/h, depending on the type.
They can hunt either alone or in packs.
general characteristics
The dwarf (or pygmy) shark belongs to the Dalathiaceae family and is the only representative of the genus Euprotomicrus. The species belongs to the order Katraniformes. The same taxon also includes the smallest shark in the world - Etmopterus perryi. However, Euprotomicrus bispinatus is only a couple of centimeters larger than it.
The dwarf shark is notable not only for its miniature size. This fish has one of the unique natural phenomena - bioluminescence. This is why Euprotomicrus bispinatus is sometimes called the dwarf luminescent shark.
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The animal uses the luminescence mechanism for protective purposes. The miniature size of the pygmy shark makes it vulnerable to larger predators. The blue glow spreading along the belly has a good masking effect in the water column, since it effectively reflects light rays. This makes the shark virtually invisible to predators swimming below. Luminescence also helps fish hunt. The soft flickering is an excellent way to attract prey.
The maximum recorded length of the dwarf shark was 27 cm. The females of these fish are larger in size compared to the males.
Habitat
Where do sharks live? The habitat depends on the species. In addition, some migrate.
The habitat of most of these fish is sea water. There is only one species that is found in the fresh water of Lake Nicaragua.
Most small species prefer to settle off the coast in warm seas. The larger ones swim in the open sea. Most often they can be found close to the surface. There are few people who prefer to live at depth. There are only a few species that are found in pitch darkness. Glowing sharks descend to a depth of more than 6 thousand meters during the day, and rise closer to the surface at night. Little is known about sharks of the deep. The choice of place where a shark lives depends on what food it prefers, size, and habits.
These fish can be found in most seas. In addition, sometimes they swim into river mouths, rising quite high upstream.
A 512-year-old shark was found in Greenland. Is it true?
Who would have thought that fish are such amazing creatures that they live much longer than humans? At the beginning of August, we wrote that a 112-year-old fish that survived two World Wars was found in the waters of the American state of South Dakota. Scientists called it the oldest fish in the world, but it seems they were very wrong. A huge shark was caught in the waters of Greenland, which, according to scientists, was born back in 1505. It turns out that she swam in cold waters back in the time of Ivan the Terrible?
Reproduction
How do sharks reproduce? Despite the fact that a shark is a fish, it does not spawn. According to the type of reproduction, they can be divided into 3 types: viviparous, ovoviviparous and oviparous. These fish are characterized by internal fertilization.
Viviparous women develop several embryos. In some species, babies eat each other while still in the womb. Because of this reproductive feature, sharks sometimes have 2 queens.
Viviparity differs from ovoviviparity in that in the first case, a placenta is produced in the mother’s body, which ensures the metabolism between the mother’s body and the embryos. In the case of ovoviviparity, such metabolism does not occur. In this case, the young hatch from eggs in the female's body and are then born. They get all their nutrients from the yolk.
Oviparous birds lay 1 to 12 eggs on average. The only one that lays much more is the polar one. She lays up to 500 eggs at a time.
How long does pregnancy last? The answer to this question depends on the species. The whale bears its offspring for more than 2 years. Pregnancy of the frilled one lasts 3.5 years. The nurse shark carries embryos for 2 years, after which 1 baby is born from each of its uteruses.
Most of these fish lack maternal instinct. A mother can eat babies that she herself has recently given birth to. In the tiger predator, nature dulls hunger before giving birth so that the young have time to escape. Some time after the female gives birth, the instinct is restored. Therefore, young animals live separately from adults and are found mainly in shallow water. Only a few species of these predatory fish care for their own children.
If there are no males, then the shark will switch from sexual reproduction to asexual reproduction. This often happens in captivity. In the wild, cases of this fish reproducing in this way have not been recorded.
What is the secret of sharks' longevity?
No matter how old a caught shark is, it is still a long-liver. At the moment, scientists are trying to figure out exactly what features of the sharks’ body allow them to live for such a long time. It was previously believed that Greenland sharks live for hundreds of years due to their slow metabolism. It’s hard to believe at first, but females reach sexual maturity only at 150 years old.
Pisces are truly amazing creatures. Some species can even change their sex if necessary. For example, this is what blue-headed thalasomas do - if there is no male in their flock, one of the females changes its color within a week and begins to behave like a male.
Fishing victims
Every year in the world from 40 to 100 million of these creatures become victims of fishing. They are caught for their fins, which are considered a delicacy, skin from which bags, briefcases, suitcases, shoes are made, teeth, liver and cartilage. Some time ago, cartilage extract was considered an effective cure for cancer. Although the effectiveness of this drug has not been confirmed, shark cartilage is considered a source of vitamins. The same applies to the liver. Teeth are used as souvenirs.
The most valuable part is the fins. Often these fish are caught just for their sake. After cutting off the fins, the fishermen throw the carcass overboard. At this point the shark is often still alive. A predator left without fins has no chance of survival. She cannot move and hunt on her own, since catching food requires speed, and will become easy prey for another predator or die from suffocation.
In recent years, many countries around the world have banned catching these fish just for their fins. Fishermen must provide the entire carcass before cutting off the fins.
Conditions of detention
In order not to condemn your pets to a joyless existence in a confined space, and even in uncomfortable conditions, you should pay attention to the peculiarities of keeping them. The decorative shark fish has a somewhat specific character and requires special attention.
Here are just the general rules:
The decorative shark fish has a somewhat specific character and requires special attention. Here are just the general rules:
- Constant water temperature – from 24 to 29°C.
- The volume of the aquarium is at least 40 liters.
- Daily change of about 30% of the water in the container.
- Good filtration and aeration of the aquarium.
As for the interior design of a glass house, you can afford almost everything. But keep in mind that under a layer of sand or small pebbles you should definitely lay a layer of large pebbles. Plants should be planted either in the soil itself, but deeper, or placed in special clay pots, carefully strengthening them. The fact is that aquarium sharks are very active fish.
For the convenience and comfort of such unusual pets, arrange several grottoes and stone caves at the bottom.
Monsters of the past
The giant megalodon is considered the largest shark to ever exist. The classification of megalodon is subject to much debate. This extinct underwater giant is currently the largest fish of all time.
Megalodon became extinct more than 2.5 million years ago. Only numerous remains have survived to this day. This huge fish was the owner of a terrifying dental apparatus. Reaching a length of up to one and a half tens of centimeters, jagged along the edges, its teeth grew in 5 rows. No animal on the planet had larger teeth. The giant jaw of sharks from the distant past exceeds human height. Currently, they are very expensive and are sold at auctions.
What do the sharks of the past look like? It is believed that megalodon was similar to a modern great white, but larger. Not a single fish existing in our time has such a size.
At the moment, not everything is known about ancient sharks. Some researchers suggest that megalodon is not actually extinct, but this has not yet been proven.
Megalolamna, which is now extinct, is also considered the closest relative of Megalodon. Little is known about sharks of this species.
How long do white sharks live?
Researchers recently concluded that white sharks can live much longer than previously thought. Using the latest technology to clearly determine the age of shark tissue, researchers were able to identify a male white shark who lived to be 70 years old .
According to scientists, such a discovery is incredibly important for animal protection, since data on the lifespan of the type, the speed of its development and the time it reaches puberty will help create programs for the conservation of the species.
Previously, researchers tried to determine the age of a predator by counting growth rings in tissue (for example, in a vertebra). But the shark skeleton contains cartilage, and the division between the rings is difficult to discern even with a microscope.
Currently, researchers have been fortunate to identify a radioactive marker in certain rings.
This marker is an isotope that fell into the ocean simultaneously with sediments after atomic bomb tests in the 60s. It settled in the tissues of animals that lived at that time.
The researchers used traces of radioactive carbon in the form of some kind of stamp, with which they can calculate and calibrate the tissue layers in order to then more accurately determine the age of the samples obtained.
Past examinations of animal remains from the Indian and Pacific oceans have led researchers to believe that white sharks live for about 30 years.
But the radioactive marker significantly increased this indicator: the largest male lived 73 years , and the female - 42 . All animals lived in the Atlantic Ocean, but scientists do not believe that there is any significant difference in the life expectancy of sharks from other oceans.
