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Text: Vientiane hardcore
Edited by Vientiane hardcore
«——【Preamble】】 ——»
The horseshoe crab, which has survived four mass extinctions, has survived on the earth for more than 400 million years, and is one of the oldest organisms on the earth, and is called the "living fossil" of the earth.
Its blue blood is more expensive than gold, and a liter was once sold for a high price of 100,000 yuan, and it was even served on the table, becoming a "good health product" in people's mouths.
The horseshoe crab has saved countless lives since it was discovered, what is so special about its blood, is the meat really that delicious, and why did it live for 400 million years and finally become endangered?
«【400 million years of "living fossils"·]»
The horseshoe crab and the dinosaurs were in the same era, or even earlier, but the dinosaurs became extinct 65 million years ago, and the horseshoe crab survived one catastrophe after another and extinctions of life to this day, how did it do it?
In the process of evolution, many species of horseshoe crab have completely disappeared, and now there are only four species of horseshoe crab left, one is the Chinese horseshoe crab that lives on the coast of the mainland.
There is also the American horseshoe crab that was first applied to the medical field, which is mainly distributed along the coast of the sea on the east side of North America, and the other is the southern horseshoe crab, which lives in Southeast Asia.
The last species is the horseshoe crab, which is found in India, Thailand and the North Sea of China, and is the only one in the horseshoe crab family that contains the toxin.
The horseshoe crab has survived 400 million years of species elimination and evolution, and it is important to note that it has a distinctive blue blood.
Why is its blood blue? Ordinary creatures are the same as humans, the blood is red, and the blue blood is very rare, and the only blue blood found so far is the octopus and horseshoe crab.
Octopuses have been around longer than horseshoe crabs, about 500 million years old, and their special blue blood is likely to be a "premium" gene that has been retained by ancient creatures as they continue to evolve.
Judging from the fossils of ancient horseshoe crabs found, the current horseshoe crab is not much different from the horseshoe crab of the ancient period, especially the most similar to the form of the horseshoe crab of the Jurassic period, which is about 200 million years ago.
Horseshoe crabs evolve slowly, their genes are relatively conserved, they are more adaptable to different environments, and they are stable enough to survive on Earth to this day.
Blue blood, in addition to being the result of ancient environmental influences, is because it has a different blood composition from most animals.
The red color of the blood is due to the presence of hemoglobin with iron, while the blue color of the blood of horseshoe crabs is called hemocyanin because of the copper contained in it.
Both hemoglobin and hemocyanin are used to transport oxygen, and in terms of function, hemoglobin has a much greater ability to transport oxygen than hemocyanin, which is also the preferred result of species evolution.
Although most animals have theoretically evolved more successfully than horseshoe crabs, they can live for 400 million years, proving that this blood of horseshoe crabs is the best choice for them.
So what is so unique about this blue blood, why did it keep the horseshoe crab alive for 400 million years of extinction, and how did humans discover the wonders of this blood?
«【The Medical Value of Blue Blood·】»
The environment in which horseshoe crabs live is mainly in shallow bays and shallow waters at the mouth of the sea, which does not require high water quality, and the sediment deposited here contains a large number of bacteria, dozens of times more than in seawater.
It survives in such an environment for a long time, and the amount of bacteria contained in the body must be a lot, and in the continuous survival of the fittest, they have evolved a kind of blue blood that is "invulnerable".
Its blue blood structure is relatively simple, and it has no "defense function", and these bacteria can enter the body of the horseshoe crab with impunity.
But horseshoe crabs can be completely unaffected because they have a special type of cell in their blood called amoeba-like cells.
How powerful is this cell? When hundreds of millions of bacteria on the beach enter the horseshoe crab's body, it immediately senses and surrounds the invading bacteria to prevent further invasion.
In 1956, a scientist stumbled upon the blood of the American horseshoe crab that coagulates the blood of infected bacteria, and this chemical reaction is so sensitive that only a small amount of horseshoe crab blood is needed to detect it.
This particular immune cell quickly caught the attention of scientists, and a special detection reagent called LAL was invented.
Since then, this reagent has been rapidly applied to the field of medical and food testing, especially in the medical field has played a huge role.
At that time, when medical treatment was not very developed, the invention of the horseshoe crab prevented many people from contracting diseases due to unhygienic and non-standard injections.
This special effect of horseshoe crab blood has made its value rise all the way, and the horseshoe crab on the seashore has also suffered and become the object of large-scale fishing, and after the horseshoe crab is caught, it will be sent to a special blood collection factory.
They are fixed to a rack and then a needle is inserted into their backs to begin collecting blood, usually no more than 50 percent per horseshoe crab, after which they are returned to the sea.
But such a blood collection can also seriously affect the reproduction of horseshoe crabs.
Horseshoe crabs have a specific breeding season throughout the year, and horseshoe crabs in China generally breed from April to August every year.
During the breeding season, both female and male horseshoe crabs climb onto the shore and dig holes in the beach to lay eggs, which can lay two to three hundred eggs at a time, which is also the best time to catch horseshoe crabs.
The horseshoe crabs that have been drawn will have a significant decrease in their reproductive ability, and their physical fitness will also regress, and a large proportion of horseshoe crabs will have a significant shortening of their lifespan after being released.
Horseshoe crabs are fished for this special function, and nearly 200,000 Chinese horseshoe crabs are consumed every year, making them very endangered.
«【Endangered horseshoe crab was eaten】»
The normal lifespan of horseshoe crabs is generally about 50 years, their growth cycle is very long, and the growth rate is also very slow, and the blood can be taken from adult horseshoe crabs, because the young have toxins in their bodies.
It takes about 15 years for a horseshoe crab to grow from the size of a fingernail to a maximum of 0.6 cm long and weighing no more than 10 catties, during which time they will undergo nearly 20 molts.
After each molt, it gains weight and its shell becomes harder.
Its back is slightly raised, similar to a crab shell, and it is very hard, which can effectively defend against foreign enemies, and it also has the ability to protect itself during the mass extinction process.
But these self-defense weapons are vulnerable to humans, and the horseshoe crab has been touted for the special medical value of its blue blood, and the horseshoe crab meat has also risen.
In many places, horseshoe crab meat is served on the table, but in fact, there is not much meat on the horseshoe crab, and the taste is not very good, and some people even say that it tastes very bitter and fishy, and no amount of cooking wine can be removed.
However, the special effect of horseshoe crab blood makes people mistakenly think that horseshoe crab meat has high nutritional value, but in fact, it is not only horseshoe crab meat, even horseshoe crab blood has no nutritional value, it can not be eaten, but it has a very significant effect on the test.
In addition, there are people who mistakenly eat round-tailed horseshoe crabs because they can't distinguish the species of horseshoe crabs, resulting in poisoning reactions in the body.
At present, the Chinese horseshoe crab is a national second-class protected animal, and wild species are strictly prohibited from fishing.
Reference:
""Horseshoe crabs" will have a period - how should Chinese horseshoe crabs be released scientifically?", 2023-11-24
Jimu News "Endangered "Living Fossil" Chinese Horseshoe Crab: Blue Blood is Used for Medical Treatment, Consuming Hundreds of Thousands of Pairs Every Year" 2023-3-28
The Paper, "This is a horseshoe crab (hòu)!, Haida people let the "blue-blooded residents" eat a "nutritious meal"!", 2022-11-21