Overview
There are many animals with different shapes and diverse living habits in nature. In millions of years of evolution and reproduction, they occupy an important position in the world's ecology. Without these magical animals, the earth would not be as full of vigor and vitality as it is today.
Among these many creatures, in addition to insects, mammals and vertebrates have a large area of distribution in this world. This is one of the most successfully evolved species on the planet. There are our own human beings, as well as birds and fish.
Speaking of creatures, people always like to label or compare these creatures according to their various habits and characteristics. For example, the fastest running, the farthest jumping, the highest flying, the longest living... From the side, these are actually what human beings are not as good as their own physical fitness, but are looking for in animals. An expression.
In addition, in the way of life of many creatures, many are surprising, and there are many problems to be solved in the research of these creatures.
"Lazy" animals
When talking about laziness in creatures, people might think of longevity . Although there is no inevitable literal semantic or actual connection between laziness and longevity, most people may think of sloth , tortoise, giant panda, koala and so on. These animals are sluggish, seem a little sluggish, and sleep most of the day.
Creatures like tortoises not only walk slowly, eat slowly, but also have a longer life span. Therefore, the laziness of organisms is naturally related to longevity.
Really long-lived animals often have a lifespan of hundreds of years. Compared with them, the life span of humans is not worth mentioning. Not to mention that human beings still need to face a variety of disease threats and natural disasters, and the overall average life expectancy is even more inadequate. In order for animals to survive, their performance in nature is often amazing.
Small-headed sleeping shark
In addition to land, there are many species in the ocean that have very long lifespans, such as some shell molluscs, sponges, jellyfish , etc., which can survive at least hundreds of years.
However, the life form of these creatures is usually very simple . Due to the physiological structure, the energy consumption of such creatures is small , and the active cells also allow them to maintain a long-lived life state.
But in the Atlantic Ocean around Greenland , there is a very peculiar fish with a very long life span, even surpassing humans’ previous understanding of the life span of vertebrates. small-headed sleeping shark, alias Greenland sleeping shark.
When you see this is a shark, you may not believe that sharks have such a long life. In our previous cognition, sharks, as the overlord of the ocean, are fierce and brutal, and bloodthirsty by nature, but their life span is generally only a few decades. The small-headed sleeping shark not only has a long life, but also has a large body size. It can also be compared with the great white shark.
The lifespan of the small-headed sleeping shark is very long,According to the existing fishing data, this shark can generally reach the 300 years old or more, and the average life span is about 275 years old . The longest-lived small-headed sleeping shark is more than 400 years old , this shark may be the longest-lived vertebrate in the world.
In appearance, the color of the small head shark is usually brown or gray , and there may be white spots or black lines on the abdomen and back. In terms of body shape, the weight of the small-headed sleeping shark is about 700-1000 kg , and the body length is more than 4 meters . Like most sharks, this shark has an unusually sharp sense of smell, and its teeth are tightly arranged and sharp.
is different from great white sharks in that small-headed sleeping sharks are slow, which is in sharp contrast with great white sharks . As a large marine predator, the small-headed sleeping shark can only swim at a speed of 0.34 meters per second , even the turtle swims faster than it.
It is also not picky in eating habits, and eats almost anything. All kinds of fish, shellfish, crustaceans, even animal carcasses or carrion. The carrion smell in the water can be quickly captured by small-headed sleeping sharks, which often gnaw on carcasses of seals in some shallow waters. Therefore, in terms of feeding habits, this shark is also a member of the scavenger .
Sacrifice eyes to eat food
As a deep-sea fish that mainly lives in 1200m water depth, small-headed sharks move slowly and survive in a dark and harsh environment , But it can still grow and prey normally. In addition, some fishermen also found some agile animals such as octopus, reindeer in the belly of small-headed sleeping sharks. Why?
This may also start with its eyes. In the research of the small-headed sleeping shark, researchers found that the eyeballs of sharks like are parasitized by a copepod crustacean .
After parasitizing the shark's eyeballs, the eyesight of the small-headed shark will be greatly weakened or even blind. Since this type of shark mainly hunts by smell, damage to the eyesight will not pose a threat to it. It can even be said that the absence of eyes makes them more capable of predation, which is also the result of biological evolution.
Copepods parasitizing the eyes can emit bio-light , which can attract many animals in the deep sea. This type of shark quietly waits for the prey to come to the door, and the almost static movement can relax the prey's vigilance and become easy to prey.
Because of this, sleeping shark , which is slow in itself, becomes more lazy. After all, their sacrificial eyes are enough to feed them.
The small-headed sleeping shark’s tail is stubby and large, which can quickly power it . In winter, this kind of shark will also lurking under the ice cave , waiting for the reindeer to approach.Then prey on . Of course, for the problem of copepod parasitism, not all small-headed sharks have this problem, and small-headed sharks also have the ability to sense light in the dark.
In the offspring breeding, they still reproduce in the shark's ovoviviparous way. However, the growth rate of this kind of sharks is unusually slow. The age at which leads to their sexual maturity is generally at 156 years old, and can only mate and reproduce at this time.
And this is only a theoretical condition, most small-headed sleeping sharks will be very passive in their mating behavior due to slow action for a long time. According to existing records, individual sharks wait a century after sexual maturity before they can mate.
Regarding the small-headed sleeping shark, some residents of the Arctic Circle, such as Iceland will catch it ashore, and then air-dried it into dried shark meat for consumption .
Because the flesh of the sleeping shark contains a lot of trimethylamine oxide , after this type of substance enters the digestive system, trimethylamine will be separated out to form a toxic substance. If people eat unprocessed shark meat, will be poisoned like drunkenness.
air-drying can deal with this toxin very well, but it should be noted that the toxins are dried in the air.The toxicity will become stronger . Air-dried sleeping shark meat has a strong smell of rancid meat. Generally speaking, few people like this kind of local specialty food.
In addition, the liver of the small-headed shark is rich in fish oil and vitamin , and it is non-toxic. This type of shark is also one of the important fish produced by the local fishery.
Biological adaptability
Small-headed sleeping sharks are related to Pacific sleeping sharks among many shark species, and these creatures all show 's strong environmental adaptability . The perennial cold climate of the Arctic Circle seems to make many animals physically stronger than animals in other regions.
In order to better survive in nature, many organisms have this similar evolution. This biological evolution can be reflected in protective color, sensory sensitivity, running speed, endurance, healing ability and so on.
For example, polar bear white fur , which can better conceal their traces to help polar bears hunt; the large area of naked body surface of humans can help us better dissipate body heat, in stone tools The times have greatly alleviated the overheating of the body caused by long-term activities of human ancestors.
The changes of the same species in different regions are also very different, as far as the shark itself is concerned. Most sharks are fast and agile, and have fast development and metabolism .The small-headed sharks are completely different. In terms of biological adaptability, the longevity and slow behavior that the small-headed sharks have evolved should be based on their biological genetics.
However, in terms of the evolution of sharks, we have not yet found the stage and species from which the small-headed shark evolved.
"Long-lived" creatures
In nature, there are many creatures with extremely long life spans. In addition to this shark, the Dawn lighthouse jellyfish on the seafloor uses a process of " differentiation and transfer" to continuously bring cells into an undifferentiated state, which makes them theoretically, as long as they are not Prey, this jellyfish can almost immortalize.
There is also water bear worm , a creature that can survive in various extreme environments. can stop its metabolism through a special dehydration method, and use trehalose to maintain the basic . The cell structure will "resurrect" again when it encounters water.
The long lifespan of small-headed sleeping sharks in vertebrates has also attracted the attention of some scientists. Based on existing research, the sleeping sharks living in the deep sea are likely to be related to their metabolism.
The heart rate of the small-headed sleeping shark is beyond ordinary people’s imagination, only beats five times per minute ,The heart of normal adults beats once per second. After people age, they are also prone to some heart-related diseases, which greatly affects the life span of human beings.
is not only a very low heart rate, but also a high level in ventricular volume . Researchers have found no evidence of atherosclerosis in their cardiac studies.
In addition, these sharks also have special immune system , which makes the small head shark extremely low risk of cancer and infectious diseases. Compared with humans, they don't have bone marrow and white blood cells, which are immune organisms. Scientists have discovered a DNA receptor called " major histocompatibility complex " on the shark.
This biological gene has more combinations of mutations, the stronger the immune system of will be. is currently only found in them. If the shark gene can be modified by gene programming , and a targeted drug with this effect can be developed, it is very likely that will enhance human survival ability in the future.
Current status of small-headed sleeping sharks
Since most small-headed sleeping sharks live in the wild, 's habitat is remote and large in size, making captive captivity very difficult . I haven’t had a detailed understanding and record of this shark before.Most of these sharks are unknown in the current research work, and many related genetic work is still undergoing experiments.
It is very difficult to record and analyze small-head sleeping sharks in the wild. In many cases, telemetry technology can be used to observe its range of motion and motion status. The direct observation of the small-headed sleeping shark's behavior is also extremely limited. Scientists currently use its foraging mechanism and predation ability to perform exercise recording and diet analysis.
In addition, since the last century, the population of sharks has gradually decreased . Climate pollution issues affects the ecology of the Arctic Circle, but the deepest impact is the impact of fishery production on its populations.
These sharks have been discovered so far that has been overfishing . In the 18th century, the annual catch of was 15,000. By 1910, the annual catch of Greenland reached 32,000 . Ship noise and industrial pollution The heavy metals brought by are also one of the threat factors of small-headed sharks. Small-headed sharks are now a near-threatened species of .
Concluding remarks
The creation of nature is always full of various variables. The strange species such as the small-headed sleeping shark is not only surprising in discovery, but may also be the secret of human longevity.
We should understand that each species of has the inevitability of its existence ,There is no reason for humans to destroy the habitat of these creatures. With the advancement of shark research and the deepening of understanding, the government has also begun to prepare various protection documents and policies. In the days to come, I believe these sharks will have a better development.
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