King Crabs: Dangerous Intruders

Who is the real king crab?

  When it comes to king crabs, the names of various king crabs often pop up in people’s minds: Alaskan king crab, Russian king crab, Hokkaido king crab, Korean king crab… Among these dazzling “king crabs”, Who is the real king crab?
  In terms of classification, although these “king crabs” have various names, they are actually the same kind of crab – Kamchatka quasi-stone crab. Names such as Alaskan King Crab are just the trade name of the Kamchatka quasi-stone crab, which is the name used when they are sold on the shelves.
  Many people mistakenly think that king crabs are crabs, but they are actually two marine animals. Crabs have 4 pairs of legs and 1 pair of crab claws. Although the king crab also has 4 pairs of legs and 1 pair of crab claws, the last pair of legs has been hidden in its carapace due to its high degree of degradation. We usually hardly see it. . In addition, the foot joints of king crabs are more flexible than those of crabs, and they can crawl both horizontally and vertically.
  If you must find a relative for the Kamchatka stone crab, it is hermit crab. The abdomen of the female Kamchatka stone crab is different from left to right, and the umbilicus grows on the left side. This is one of the main characteristics of hermit crabs, and it is also the reason for the asymmetry of the female Kamchatka stone crab as an adult.

King Crabs: Invaders in the Barents Sea

  The Barents Sea is located in the north of Norway and Russia, and is named after the Dutch navigator William Barents who died in this sea. Although the Barents Sea is a continental marginal sea of ​​the Arctic Ocean, due to the warm current in the North Cape, its southern sea surface does not freeze all year round, and the warm current brings nutrients into the sea area, providing sufficient food for fish. Therefore, the Barents Sea has become an important fishing ground for the region.
  In the 1960s, Soviet scientists brought five king crabs to the Barents Sea and released them back into the sea. King crabs live in cold, deep seas, and from April to June every year, they climb the shallows to lay their eggs. The Barents Sea is very suitable for the reproduction of king crabs in terms of temperature and terrain, so they “settle down” here.
  A year later, Soviet scientists came to the Barents Sea again. They were surprised to find that these king crabs had grown from 5 to tens of thousands. This means that each female crab can produce nearly 10,000 live young crabs every year, and the reproduction rate is amazing. However, this is not a good thing, because this invasion of king crabs has only just begun.
  With global warming, some king crabs have migrated from the waters south of the Barents Sea to the Svalbard archipelago to the north, and because they have few natural enemies there, they naturally become top predators. The arrival of the king crab is a catastrophe for the Svalbard ecosystem. In recent years, the destruction of ecosystems caused by the savage breeding of king crabs has attracted widespread attention from scientists.

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  Kamchatka stone crab

  Chinese name: Kamchatka Stone Crab
  Aliases : Hokkaido King Crab, Alaskan King Crab, Cod Crab
  Family and
  Genus From the Sea of ​​Okhotsk to the Bering Sea
  Appearance : It looks like a crab. It only has 3 pairs of walking legs from the outside, but in fact it has a pair of mini walking feet hidden in the carapace. This pair of short, small feet took on the job of cleaning the gill chambers.
  Body Shape: The average weight is 10 kg, the width of the carapace can reach 28 cm, and the length of the wingspan can reach 1.8 meters.
  Lifespan: about 30 years
  Temperament : Relatively ferocious
  Special skills: Regeneration of severed limbs
  Food : benthic animals and algae
  Natural enemies: almost none
  Lifestyle : like to get together in the cold deep sea, the habitat depth can reach 800 meters, the most suitable for living The water temperature is between 2 and 5 °C, and the minimum water temperature that can be lived is 1.4 °C.

King crabs are “invading” Antarctica!

  The increasingly serious greenhouse effect not only causes global warming, but also makes many species face a crisis of survival, even the king of the Arctic such as the polar bear is no exception. But the list of victims definitely doesn’t include king crabs. As beneficiaries of global warming, king crabs are working to expand their sphere of influence, such as “invading” Antarctica.
  As early as 2011, remote-controlled submarines discovered more than 1 million king crabs migrating here in the “Palmer Deep Sea”, a mudbed basin located 850 meters below the continental shelf off Antarctica. They are huge in size, with a wingspan of about 1 meter. King crabs are not native to Antarctica, so how did they appear in Antarctica? Scientists speculate that this may be the warm water flowing through the “Palmer Deep”, bringing a large number of juvenile crabs. Because the water temperature here is suitable for king crabs to live, the young crabs from afar have set up camp here and thrived.
  The average temperature in Antarctica is -25°C, which is very cold. Even in summer, Antarctic waters are still a mixture of ice and water. The Antarctic continent is surrounded by thick ice sheets, and white icebergs float on the sea. Glaciers on the edge of the land will also collapse and fall into the sea, which makes the deep water relatively warmer, and the closer to the sea surface, the colder it is.

  In the past 14 million years, king crabs have never set foot in the waters of the Antarctic continental shelf. This is because for them, there is a natural low temperature barrier in the Antarctic waters, preventing them from reaching the Antarctic. However, with global warming, the temperature of the once habitable place for king crabs has increased, and the living environment has become harsh, while the Antarctic has become a suitable place for king crabs to live because of the increase in temperature. In order to make their lives better and their families stronger, it is natural for king crabs to migrate to more livable places.

  King crabs are top predators, and once they invade an area of ​​water, they will quickly wipe out their competitors. Scientists discovered through remote-controlled submarine exploration that there are a large number of plants and animals living above the waters where the king crab lives, including echinoderms such as sea snaketail, crinoids and sea cucumbers. However, in the waters where the king crab is located, none of these echinoderms can be found. Even if you go up 50 to 100 meters from here, the number of animals found is still very small. This means that king crabs devour prey in the waters they control.
  The minimum water temperature for king crabs to survive is 1.4°C. Once the water temperature on the Antarctic shelf rises to 1.4°C, the king crab can completely ignore the low temperature barrier of the Antarctic sea and enter the Antarctic shelf. Scientists believe that if the trend of global warming does not change, the king crab will be able to conquer the Antarctic continental shelf in just 20 years. By then, the ecological environment of the Antarctic continental shelf will face a catastrophe.

  Bering Sea’s annual Brave Competition is coming soon. For the young king crabs participating for the first time, this competition is their coming of age ceremony. “Victory” means that they have the qualifications to start a family; “failure” means there is no future, because all losers will become delicacy on the human table.
  King crabs have known the principle of “natural selection, survival of the fittest” since childhood. Only the brave can inherit their excellent genes. This is why the king crab family has prospered for generations.
  In order to help these young king crabs who are vigorous but inexperienced, the clan specially arranged for experienced elders to teach them.
  ”These are human crab pots.” The elder drew various crab pots.
  Victor listened carefully, trying to remember the appearance of these crab pots.
  ”Hey, don’t you think listening to the class is too boring?” Xi stretched out a big claw and poked it.
  Victor ignored it and continued to listen carefully.
  ”Even if the food is delicious, be prepared to run away at any time.” The elder waved his big claws and said excitedly, “We are the famous king crab, and we can’t be carried away by the food!”
  ”Well, not only Thinking of eating.” Victor repeated the point softly.
  ”Hey!” Sheila poked harder.
  Victor still ignored it.
  ”You can’t give up hope at any time. Even if you fall into the crab trap, you still have a chance to escape!”
  ”Well, you can’t give up hope!” Victor looked at the elder admiringly.
  ”This old man’s words are stupid, do you really believe it?! Then you are as stupid as him…” Sheila sneered.
  Just then, a huge king crab rushed into the classroom. The elder exchanged a few words with it in a low voice, and then announced: “The human crab boat is heading here.”
  The day when the crab boat arrives, is when the king crab’s brave competition begins. Today is the last time for everyone to attend the training. At the end of school, the elders sent blessings to them, hoping that they can all win the brave competition.
  ”Thank you, elder.” Victor thanked the elder a little shyly.
  ”Old man, I will definitely come back alive!” Sheila stretched out her long legs habitually and put them on Victor’s body, “Don’t be afraid, I will cover you.”
  ”Your relationship is really good. “The elder couldn’t help laughing when he saw this. Although Victor was shy by nature, the elders still noticed this serious study child.
  ”That’s right, we are children.” Sheila said carelessly.
  Victor smiled as shyly as ever.
  This colony of king crabs lives in the Bering Sea, one of the most treacherous and unpredictable seas in the world. Crab season starts in January every year, when it is winter, the days are extremely short, the snowstorm is the most violent, and the sea surface temperature will drop to -10°C.
  Crab boats are enveloped in a thick layer of ice, making it harder to keep their balance in rough seas. Crab catchers not only have to endure severe cold, but also tormented by winds of 128 kilometers per hour and huge waves as high as 12 meters. According to statistics, about 1/7 of crab catchers stay in that sea forever every year. It is for this reason that this work is considered very dangerous.
  For king crabs, these crab catchers are the touchstones of their growth, and only the brave can escape the crab catchers’ pursuit. Victor and Sheila once thought that being a hero must have a very high value of force, but they didn’t know until now that what they had to fight against was their own instincts!
  With so many king crabs gathered in the arena, all that could be eaten was quickly exhausted. In order to catch king crabs, crab catchers put delicious bait in crab pots. In these days, Victor and Sheila have witnessed too many of their own kind who have fallen into the trap because they can’t resist the temptation…
  At first, Victor and Sheila were able to resist the temptation. Later, because they could not find other food, they also had to risk food from the cage. Victor’s force value is not high, so these days, he mainly relies on the food that Sheila grabbed to maintain his life.
  ”Are we going to starve to death?” Victor felt that he was dragging Sheila’s back, which made him feel a little down.
  ”How could I starve to death?” Sheila habitually put her long legs on Victor.
  ”Sheila, it’s nice to have you.” This made Victor feel a lot more at ease.

  ”Nonsense, but you are not bad. Only as smart as you can remember those words of the old man.” It turned out to be the experience taught by the elders, which made them escape several times.
  ”I’m not that smart, I just study hard. If you study hard, it will be the same…”
  ”Don’t listen, don’t listen.” Sheila covered her ears.
  At this time, a crab cage fell, and the large pieces of bait in the cage looked particularly attractive. After these days of training, everyone knows that only when the number of king crabs in the crab cage reaches a certain number, the crab catcher will close the cage. So it is safest at first, and then the risk increases with the number of king crabs. So if you want to grab food in the cage, you must not only look at the timing, but also move fast enough.
  In an instant, many king crabs rushed up.
  ”Stay where you are and wait for me!”
  ”Be careful… be careful!” Before Victor could finish speaking, Sheila had already rushed out.
  Sheila moved so fast that it grabbed the food, and many king crabs didn’t have time to react. By the time they reacted to the bait, Sheila had already started to withdraw. This little time difference is the secret of its ability to get out of the body every time.
  Sheila breathed a sigh of relief as she was about to leave the crab trap. At this moment, the crab pot suddenly rose rapidly. It watched helplessly as the open cage mouth got smaller and smaller… All the king crabs still in the crab cages rushed towards the narrowed cage mouth frantically.
  ”Sheila!” Victor quickly found out that something was wrong and chased after the crab pot. But how can it catch up with the crab pots controlled by modern machinery.

  It could only watch helplessly as the crab pots rose higher and smaller… and finally disappeared. That is, at this time, the crab fishing task of those crab fishing boats was completed. This year’s crab fishing season is over, and all surviving king crabs will be awarded the title of brave and have the qualifications to reproduce.
  All the surviving king crabs were cheering.
  ”If you lose Sheila, what’s the point of becoming a hero?” Victor said in despair.
  ”Hey!” came a voice suddenly.
  Victor didn’t notice the voice at all.
  ”Hey! Don’t you think I’m ugly, so you don’t want to recognize me?!” Sheila wanted to put her long legs on Victor like before, but she fell down with a “click”.
  ”You, you haven’t been captured?!” Victor finally came back to his senses.
  Only then did it discover that Sheila had only five long legs that she had always been proud of. It is also because of this that Sheila, who has always been agile, is now a little unsteady when she walks. It turned out that Sheila remembered Victor’s advice, and never left the door of the crab cage when feeding. When the crab cage rose, she tried her best to open the door with her legs, and she struggled to break one leg, but her life was saved. .
  ”Welcome back.” Victor’s eyes were wet, he stretched out his claws and touched Sheila, “Sheila, you are my warrior.”
  ”Well, you are also my warrior!” Sheila also touched with her claws. Touch Victor.
  The two king crabs looked at each other and smiled. The next moment, Victor put his long legs on Sheila’s body: “It really feels good to do so.”
  ”My long legs will definitely grow again!” Sheila said loudly.