What kind of deep-sea monster is the shark that bit the U.S. submarine?
Sharks are iconic animals in the ocean. There are currently about 500 species of sharks discovered by humans, which are widely distributed in seas around the world.
Different sharks have different body types. The largest whale shark can be more than 12 meters long, and the smallest pygmy dogfish is only 20 cm long.
Although there are differences in size, sharks are all carnivores without exception, and their hunting methods are also different.
Large white sharks use ambush predation methods, they have sharp teeth and agile speed; bigger, such as whale sharks, open their mouths to inhale fish and shrimp, and then discharge the seawater.
Some smaller sharks mostly use parasitic hunting. Parasitic hunting means attaching to prey and then gnawing their meat.
The representative shark is the cigar Dharma shark. We may not be familiar with this shark, but there are many "fishes" who have experienced their power in the water.
Their methods of attack are so brutal and brutal that the victims often die in pain, even if they survive, they will be severely injured.
"Cigar" in the ocean
The cigar Dharma shark, also known as the Brazilian Dharma shark and Dharma Jiao, is a small shark that lives in the mid-latitude oceans, the Central Pacific and the Sea of Japan. It belongs to the genus Kodama shark.
Male cigar Dharma shark has a body length of up to 42 cm, female body length can be up to 56 cm, and it looks like a cigar, hence the name.
Unlike common fish that move in the horizontal range, the cigar daruma shark often swims vertically between 0-3500 meters in water depth, and can dive at the deepest 3700 meters.
When the sun is about to come out, they start to dive, and when the sun is about to set, they return to the shallow sea, and their vertical travel can reach 3 kilometers per day.
A "devil" face
Although it looks like a cigar from a distance, if you look closer, you may be scared by the looks of this guy. Some people even call it a devil.
Their body is long and slender, the head is short and round, the nostrils are at the front end, and a pair of big green eyes like eggs are inlaid on both sides of the head, but they do not have binocular vision.
The pectoral fin is short and trapezoidal, the two dorsal fins are relatively behind, the pelvic fin is obviously larger than the dorsal fin, the caudal fin is the widest and the upper lobe has obvious notches.
Their mouths are not much different from ordinary sharks, they are split into an arc at the back, but there is an extra layer of wing-like pleats on the periphery of the mouth.
The most distinctive thing is their teeth. The teeth of the upper and lower jaws of the cigar daruma shark are not the same. The upper jaw teeth are narrow and smooth, and the lower jaw teeth are wide and connected in a row, just like a saw.
And this kind of weird tooth is their big killer, taking away the flesh of countless animals, leaving them infinite pain.
Cruel and hidden hunting methods
Cigar Dharma sharks are never picky eaters, as long as they are marine creatures that overlap with their habitat, they can be their prey, no matter how big they are.
The light on their abdomen can emit light similar to sunlight, which helps to weaken their silhouette and reduce the chance of being spotted by predators below.
At the same time, there is a dark band in their pharynx that does not emit light. This is thought to mimic the silhouette of a small fish and use it as a bait to attract prey.
The mouth of the cigar Dharma shark can be opened to a great angle, almost into a circle. The highly calcified skull and labial cartilage provide it with a strong bite force.
After confirming the prey, they will quickly stick the sucker-like mouth to the prey's body, then close the spray hole and lower the hyoid bone, so that the oral pressure is lower than the outside, thereby forming a strong suction.
Next, they will use the small and sharp upper jaw teeth to fix on the surface of the prey, and bite into the meat of the prey through the larger lower jaw teeth.
Finally, the cigar daruma shark will twist and rotate its body sharply, biting out the meat of the prey, just like pulling out a stopper from the bottle mouth.
The bitten prey will leave a cylindrical wound with a diameter of 5 cm and a depth of 7 cm. The flesh and blood are clearly visible, which is very tragic.
This iconic round wound has been found on dolphins, seals, fur seals, great white sharks, sperm whales, megamouth sharks, and killer whales, which is enough to show that they are "doing a lot of evil."
In addition, they usually feed in groups and tend to attack sick or young prey. Someone even found hundreds of wounds left by cigar daruma sharks on a stranded melon-headed whale.
Not even letting go of the submarine
The cigar daruma shark lives deep in the ocean and basically has no intersection with the human habitat, but some people who swim or take pictures in the ocean have been bitten by them.
It is not uncommon to be attacked by creatures in the ocean, but the cigar daruma shark not only bites people, but also bites submarines. The submarines of the US military have been attacked.
In the 1970s, the sonar domes on several American submarines were damaged by cigar Dharma sharks, resulting in the leakage of oil used to conduct sound waves.
Interestingly, at first, the U.S. military didn't know that sharks destroyed the sonar, but thought it was a new weapon of the enemy, and was panicked for a while.
After finding out the reason, they installed fiberglass on the sonar dome. Since then, the sonar on the submarine has never been damaged.
Actually, not only submarines, cigar daruma sharks often damage the insulation of submarine cables and some oceanographic equipment, and sometimes bite fishing nets.
Some people say that the cigar Dharma shark is like a flea in the sea, but even in front of a big shark, it is a huge flea that does not suck blood and only eats meat.
However, great white sharks should not feel pain, because they do not have nociceptors, but some bony fish may feel it.
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