When it comes to sharks, many people's first impression is "the overlord in the sea", in the field of film and television, we can often see works with sharks as the protagonists, which all unexpectedly set up a fierce and terrifying image. It is true that sharks are predators in the sea, equivalent to the position of tigers on land, people who go to the sea to swim or surf, in addition to being afraid of natural forces such as huge waves, the most feared thing is to encounter sharks, once entangled in sharks, it is really possible to die nine times.
Great white sharks
Everyone knows sharks, but in fact, sharks are a very large concept, at least not a specific species, but refers to a class of medium and large marine fish, a total of 8 orders and 25 families of about 470 species, including 4 species that have been extinct, of which about 130 species of sharks live in China's waters.
However, humans know very little about marine life, and as far as the current research is concerned, it is not possible to fully determine that there are so many shark species, not to rule out that there are still populations that have not yet been discovered, and it is not excluded that some species may be extinct.
Six-gill sharks, with 6-7 gill holes, 1 dorsal fin, fin, no hard spines;
Porbeagle sharks, with 10 gill holes, 2 dorsal fins, fins, no hard spines;
Tiger sharks, with 5 gill holes, 2 dorsal fins, fins, hard spines;
True sharks, with 5 gill holes, 2 dorsal fins, fins, no hard spines;
Horned sharks, with 5 gill holes, 2 dorsal fins, no fins, with hard spines;
Sawsharks, with 5-6 gill holes, 2 dorsal fins, no fins, no hard spines;
Flattened sharks, with 5 gill holes, 2 dorsal fins, no fins, no hard spines;
It has 10 gill holes, 2 dorsal fins, fins, and no hard spines.
Whale
In general, most sharks are long spindle-shaped, with cheeks on both sides of the head, hard skin, dark gray, 80% of shark species are under 160 cm in length, the largest shark is the whale shark, which is also the world's largest non-cetacean, the average adult whale shark weighs 9 tons and has a body length of 9.8 meters, of which the upper limit is not very certain at present, of which there are reported to be more than 18 meters of whale shark samples.
There are probably more than 20 kinds of sharks in the world that attack humans, of which the most attacked humans are great white sharks, pelagic whitetip sharks, tiger sharks and bull sharks, so not all sharks are deadly.
Flat shark
The vast majority of sharks in the world are meat-eating, some sharks attack actively, they take the initiative to look for prey, find the prey when they impact it at a very fast speed, and then bite the flesh of the prey with sharp teeth, and then twist the body vigorously, tearing the meat down, the whole feeding process is very ferocious. Some submarine sharks use ambushes, such as flat sharks, which rely on camouflage to wait for their prey to arrive and then suck it into their mouths. Some benthic sharks, on the other hand, eat only crustaceans, and their teeth evolve to be flattened, capable of grinding the shells of crustaceans.
Promotional photos for the movie Jaws
Whenever there is a news report of a human being being attacked by a shark, it will cause concern all over the world, coupled with the publicity of many film and television works over the years, making people shudder at this sea creature, many ordinary people will even consider buying shark repellent when they go to the beach to play in the water, but in fact, it is not necessary, "Jaws" director Steven Spielberg later tried to change the murderous image created by the film in people's minds.
In addition, the vast majority of people who stay in the sea every day have not been bitten by sharks, and sharks rarely run to the shoals of human activity, but this is not absolute.
On the study of shark feeding habits, experts have concluded that sharks actually do not like to feed on humans, and they will not actively hunt people who fall into the sea, but sharks are likely to treat people as invaders and launch attacks, because in the eyes of sharks, they are not accustomed to seeing sudden people break in, which will frighten sharks and attack.
In addition, sharks are likely to eat people by mistake, for example, when a person is in some small fish, the shark may bite humans when preying.
A long time ago I heard a joke that sharks don't eat people, but out of curiosity they will go up and take a bite, find that it is not food, and then go, and then the next shark is curious to take a bite, find that it is not food and go, and so on, people are eaten by sharks, although this is a joke, but now it sounds like the same thing as accidental eating.
In fact, the shark's intention to attack humans or other animals is elusive, at least for now, and it is not a simple relationship between predation and predation.
Sharks are distributed in the world's oceans, and they are quite widespread, so are sharks in each sea area attacking humans the same? Obviously not, according to the data on the archives of shark attacks recorded around the world, it can be seen that there are many more shark attacks on humans in the Atlantic than elsewhere, for example, in 2018, in the United States, there were 27 shark attacks on humans in the Atlantic, while only 4 in the Pacific, the difference between the two is too large.
Blacktip sharks
There are many reasons for this difference, the Atlantic ocean currents shoot warm waters towards the shore, which attracts more other small fish, and the increase in small fish is bound to attract more predatory fish such as blacktip sharks.
In addition, the warm water also attracts more humans to play in the sea, while increasing the length of time people stay in the sea, on the one hand, the number of sharks, on the other hand, the increase in human beings, staying in the sea for a long time, then the probability of sharks attacking humans is bound to increase.
Tiger shark
In addition, it is also related to the type of shark, such as in the Atlantic Ocean, the sharks that attack humans are generally small, and the biting sharks in the Pacific Ocean are more large sharks such as great white sharks, tiger sharks, bull sharks, etc. The same is on the shoals of human activities, small sharks are easier to dive in, and large sharks are easier to be found in addition to being stranded, which greatly reduces the probability of being attacked by sharks. So if you look at the number of attacks on humans alone, atlantic sharks attack humans more often.
If you look at the shark attacks on humans from a simple perspective on the past long period, they are increasing, but if you look at the data in recent years, they are decreasing, for example, there were 98 shark attacks on humans in 2015, and in the whole year of 2018, there were only 66, which is much less, which may be some news reports that have played a deterrent role, making people more afraid of this creature, so they will be extra careful when they are active in the ocean.
According to the global shark attack archives, there have been 6,200 shark attacks on humans from the 16th century to the present, but this data is not entirely accurate, because in the past years when the internet was not developed, some of the smaller attacks were likely to go unreported.
Last year, in 2018, there were a total of 130 shark attacks on humans worldwide, of which 66 were shark attacks on humans for no reason, 34 were shark attacks caused by some factors, and some were attacked for a variety of reasons, such as divers trying to touch sharks, being attacked when feeding sharks, and so on. Of those 130 incidents, 5 were fatal.
The data on 66 unprovoked attacks on humans is lower than in previous years, with an average of 84 shark attacks on humans per year from 2013 to 2017.
In the global shark unprovoked attack on humans, the most occurred place is the United States, accounting for 48% of the global total, followed by Australia, accounting for 33%, of which the largest area in the United States is Florida, a total of 16 cases in 2018, accounting for 50% of the total number of the United States, accounting for 24% of the world total, but from the data of 16 cases in Florida last year, it has been far below the average of 30 cases per year in the past 5 years, the following specific data:
In 2018, there were 66 unprovoked shark attacks on humans worldwide;
There were 32 cases in the United States throughout the year, 1 of which resulted in deaths;
There were 20 cases in Australia throughout the year, 1 of which resulted in fatalities;
There were 3 cases in Brazil throughout the year, 1 of which resulted in fatalities;
There were 3 cases in Egypt throughout the year, 1 of which resulted in deaths;
There have been 2 cases in the Republic of South Africa throughout the year, with no deaths;
One each occurred in the Bahamas, Costa Rica, galapagos, New Caledonia, New Zealand and Thailand, with no deaths.
Although being attacked by sharks is a very scary thing, you can't dare to go into the water because you are afraid, which is a bit of a choking feeling. In addition, compared with other accidents, the probability of being attacked by sharks is much smaller, or even less than the probability of being struck by lightning, for example, in 2018, there were 130 shark attacks on humans, and millions of people around the world were killed or injured in car accidents this year.
Although our human strength seems to be very small when we encounter shark attacks, if we take some precautions, we can minimize the probability of encountering sharks.
Sharks have a very keen sense of smell, so if they have wounds on their bodies that are bleeding, or when they are menstruating in women, it is best not to go into the water;
Try to go to places with many people, because sharks like to attack single humans;
Don't spend too long in the sea at dusk or in the dark, as sharks are likely to be unable to tell if you're a human or another fish;
Do not wear some reflective ornaments, because these reflective ornaments are likely to become flashy under the sun' illumination, so that sharks will mistakenly think that they are other fish;
When you see a school of small fish, don't get close because you are curious, or even be in the middle of the fish, which is very dangerous, because these fish will attract sharks;
If you're diving in an aquarium, it's best not to touch a shark, especially its tail, out of curiosity.
Of course, the above practices do not help you to absolutely avoid encountering sharks, but it is only to minimize the probability, in short, it is necessary to play in the sea and be careful everywhere. Although sharks look very strong, let people talk about shark discoloration, but in fact they are also very fragile, at present due to human shark hunting operations, resulting in a sharp decline in the number of sharks, most of them are on the verge of extinction, human harm to it, far more.