What is the essence behind the shark attack?

When it comes to sharks, what are many people's first impressions? Overlord in the sea In the field of film and television, we can often see works featuring sharks, all of which set up a fierce and horrible image. It is true that sharks are predators in the sea, equivalent to the status of tigers on land. People who go swimming or surfing in the sea are most afraid of meeting sharks besides natural forces such as huge waves. Once entangled in a shark, it may really be a narrow escape.

Great white shark

Everyone in the shark family knows about sharks, but in fact, sharks are a very big concept, at least not just a specific species, but a class of medium and large marine fish. There are about 470 species belonging to 25 families of 8 orders, of which 4 species have been extinct, and about 130 species of sharks live in China's waters.

However, human beings know little about marine life. According to the current research, we are not sure that there are so many kinds of sharks. It does not rule out that there are undiscovered populations, nor does it rule out that some species may become extinct.

Six-gill shark, with 6-7 gill holes, 1 dorsal fin and gluteal fin, without hard spines; Rat shark, 10 gill hole, 2 dorsal fins, gluteal fins, no hard spines; Tiger shark, with 5 gill holes, 2 dorsal fins, gluteal fins and hard spines; Real shark, with 5 gill holes, 2 dorsal fins and gluteal fins, without hard spines; Hornoptera, with 5 gill holes, 2 dorsal fins, no gluteal fins and hard spines; Saw shark, with 5-6 gill holes, 2 dorsal fins, no gluteal fins and no hard spines; Flat shark, with 5 gill holes, 2 dorsal fins, no gluteal fins and no hard spines; Stipules, with 10 gill holes, 2 dorsal fins and gluteal fins, without spines. whale shark

Generally speaking, sharks are mostly spindle-shaped, with cheeks on both sides of the head and hard and dark gray skin. 80% shark species are below 160 cm in length. The biggest shark is whale shark, and it is also the largest non-cetacean animal in the world. Adult whale sharks weigh an average of 9 tons and are 9.8 meters long. The upper limit is still uncertain, and some are reported.

There are about 20 kinds of sharks that attack humans all over the world, among which great white sharks, pelagic whitetip sharks, tiger sharks and bull sharks attack humans the most, so not all sharks are fatal.

Scottina

Most sharks in the world eat meat. Some sharks take the initiative to attack. They take the initiative to look for prey, and when they find it, they pounce at a very fast speed, then bite the meat on the prey with sharp teeth, and then twist their bodies hard to bite off the meat. The whole eating process is vicious. Some sharks that live on the bottom of the sea will lie in ambush, such as the flat shark. They wait for their prey by camouflage and then suck it into their mouths. Some benthic sharks only eat crustaceans, and their teeth have evolved into flat shapes that can grind crustaceans' shells.

A promotional photo of the movie Jaws

Sharks don't really like to eat people. Every time there is a news report that humans are attacked by sharks, it will attract the attention of the whole world. In addition, the publicity of many film and television works in recent years has also made people shudder at this marine life. Many ordinary people go to the beach to play with water and even consider buying shark repellent, but it is not necessary. Steven, director of Jaws? Spielberg later tried to change the cruel image that movies created in people's minds.

In addition, most people who stay in the sea every day have never been bitten by sharks, and sharks rarely come to shoals where human activities are carried out, but this is not absolute.

According to the research on shark's feeding habits, experts have come to the conclusion that sharks actually don't like to feed on humans, and they don't take the initiative to prey on people who fall into the sea. It's just that sharks are likely to attack people as intruders, because in the eyes of sharks, they are not used to seeing people suddenly break in, which will scare sharks and launch attacks.

Besides, sharks are likely to eat people by mistake. For example, if a person is in a group of small fish, sharks may bite when they are hunting.

A long time ago, I heard a joke that sharks don't eat people. They just take a bite out of curiosity, find it's not food, and then leave. Then the next shark asked for a bite out of curiosity and found that it was not food that left again. If this cycle continues, people will be eaten by sharks. Although this is a joke, it seems to have the same effect as eating by mistake.

In fact, the intention of sharks to attack humans or other animals is elusive, at least for now, and it is not a simple relationship between predation and prey.

Sharks in the Atlantic prefer to bite. Sharks are distributed in oceans all over the world, and they are quite extensive. So is the attack behavior of sharks on humans similar in every sea area? Obviously not. According to the data recorded in the archives of shark attacks on humans around the world, the number of times in the Atlantic Ocean is much more than that in other places. For example, on 20 18, in the United States, there were 27 shark attacks on humans in the Atlantic Ocean, while there were only four in the Pacific Ocean, which was a big difference.

Black fin shark

There are many reasons for this difference. The Atlantic ocean current brings warm water to the shore, which attracts more other small fish. More small fish will inevitably attract more predatory fish such as black fin sharks.

In addition, the warm sea water attracts more people to play in the sea, and at the same time, it also increases the time people spend in the sea. On the one hand, there are more sharks, on the other hand, there are more people who stay in the sea for a long time, so the probability of sharks attacking people will inevitably increase.

spiny dogfish

In addition, it is also related to the types of sharks. For example, in the Atlantic Ocean, sharks that attack humans are generally small, while in the Pacific Ocean, there are many large sharks such as great white sharks, tiger sharks and bull sharks. Similarly, in the shallows where human activities are taking place, small sharks are more likely to sneak in, while big sharks are more likely to be found except stranded, thus greatly reducing the probability of being attacked by sharks. So if we only look at the number of attacks on humans, Atlantic sharks attack humans more frequently.

People and sharks, if we look at it for a long time in the past, the number of shark attacks on people is increasing, but if we look at the data in recent years, it is decreasing. For example, in 20 15, there were 98 shark attacks on human beings, while in 20 18, there were only 66 attacks, which was much less. Perhaps some news reports have played a deterrent role, making people.

According to the global shark attack archives, from16th century to now, there have been 6200 shark attacks on human beings. But this data is not accurate, because in the past, when the Internet was underdeveloped, some relatively small attacks probably would not be reported.

Last year, that is, in 20 18, there were 130 shark attacks on humans around the world, of which 66 were unprovoked attacks on humans, 34 were caused by some factors, and others were caused by various reasons, such as divers trying to touch sharks and being attacked while feeding them. Of these 130 incidents, 5 were fatal.

Judging from the data of 66 unprovoked attacks on human beings, it has been lower than previous years. From 20 13 to 20 17, an average of 84 shark attacks on humans occurred every year.

In the global shark attacks on human beings without reason, the place with the highest frequency is the United States, accounting for 48% of the global total, followed by Australia, accounting for 33%. Among them, the most frequent occurrence in the United States is Florida, with 16 and 438+08 in 2065, accounting for 50% of the total in the United States and 24% of the total in the world. However, since Florida last year, it has been 65438.

In 20 18, there were 66 incidents in which sharks attacked humans for no reason. There were 32 cases in the United States, of which 1 case led to death; There were 20 cases in Australia, of which 1 case led to death; There were 3 cases in Brazil in the whole year, of which 1 case led to death; Three cases occurred in Egypt throughout the year, of which 1 case resulted in death; Two cases occurred in the Republic of South Africa throughout the year, and no one died; Bahamas, Costa Rica, Galapagos Islands, New Caledonia, New Zealand and Thailand 1 case, no one died. How to avoid being attacked by sharks? Although being attacked by a shark is a terrible thing, you can't be afraid to go into the water because of fear. It's a bit like choking on food. In addition, compared with other accidents, the probability of being attacked by sharks is much smaller, even less than the probability of being hit by lightning. For example, in 20 18, there were 130 shark attacks on human beings, and millions of people were killed or injured in car accidents around the world this year. Comparatively speaking, the accident probability of crossing the road is greater than that of being bitten by a shark.

Although we humans are weak when attacked by sharks, if we take some preventive measures, we can minimize the probability of encountering sharks.

Sharks have a keen sense of smell, so if you have a wound that is bleeding, or are in a female physiological period, it is best not to go into the water; Try to go to crowded places, because sharks like to attack lonely humans; Don't stay in the sea for too long in the morning or in dim light, because sharks may not know whether you are human or other fish; Don't wear some reflective ornaments, because these reflective ornaments are likely to flash in the sun, so sharks will be mistaken for other fish; When you see a group of small fish, don't get close because of curiosity, or even be among a group of fish. This is very dangerous because these schools of fish will attract sharks. If you dive in the aquarium, you'd better not touch the shark, especially its tail, just out of curiosity. Of course, the above practice can't help you absolutely avoid meeting sharks, just minimize the probability. In short, you must be careful when playing in the sea. Although sharks look tough and scary, they are actually very fragile. At present, due to human shark hunting, the number of sharks has dropped sharply, and most of them are on the verge of extinction. Humans do much more harm to them.