21 Creepy Facts About The Japanese Spider Crab

We all know that crabs aren’t the cutest animals in the world. But the animals you’ll discover now are straight-up frightening.

Arachnophobia isn’t the rarest phobia in the world because a lot of people suffer from it. It’s fair to assume that these creepy ocean creatures might make this particular phobia of scary spiders even more common.

Get ready, because, in this post, You’ll learn all the facts about the Japanese Spider Crab.

1. What are Japanese Spider Crabs?

The Japanese Spider Crab also referred to as the “Macrocheira kaempferi” or takaashigani in Japanese (“long-legged crab”), is a type of crab that lives in the ocean around Japan. It has extremely long legs and resembles a giant spider.

The name “Long-legged crab” wasn’t invented for no reason. This type of crab has huge legs compared to its small carapace. This gives it a particularly creepy look.

facts about the Japanese spider crab
Japanese Spider crabs have long legs / Wiki Commons

2. Where do Japanese Spider Crabs live?

The Japanese Spider crab lives mostly on the pacific side of the Japanese islands. They are mostly found in the Sagami, Suruga, and Tosa bays, as well as off the coast of the Kii peninsula.

They live at a depth of about 50-600 meters (164 to 1968 ft) and usually inhabit the sandy and rocky slope of the ocean near the land at an average depth of about 200 meters (656 ft).

3. Will I ever come eye to eye with any of these?

You’re chilling on a Japanese beach not too far from your comfortable hotel in Tokyo. It’s a hot summer day and you walk towards the beach bar to order some mojitos.

And then it happens, one of those long-legged monsters is sharpening its claws, ready to attack and have a battle royale with you in your swim shorts.

Is this scenario possible?

Don’t worry, it won’t happen, go ahead and order that mojito!

If you’re not trying to catch one in the ocean there is no way you’ll ever come across a Japanese Spider Crab. They do move to more shallow water every now than during the mating season, and the young Japanese Spider Crabs prefer more shallow waters as well.

But the bigger they get, the deeper they go so it’s very unlikely one of these monsters will bother you in any way.

Japanese spider crab facts
Japanese spider crabs solely live in the ocean / Source

4. One Japanese Spider Crab got a bit lost one time

One time, a particularly lost Japanese Spider Crab was found far away from its natural habitat. It was found over 1,000 kilometers south in Su-ao, in Eastern Taiwan.

It’s most likely that this unlucky fellow was swept away by a storm, or he got a ride on a fishing boat somehow and ended up where none of his relatives ever went before.

5. Japanese Spider Crabs are huge

While the carapace of this crab is only about 35-40 centimeters long, the complete span of adult Japanese Spider crabs can reach up to 5.5 meters (18 ft) long.

This is determined when all its legs are spread out and the length is measured from claw to claw.

6. They grow bigger in time

When the Japanese Spider crab reaches adulthood, its carapace remains pretty much the same for its entire lifetime.

The legs, on the other hand, keep on growing for the rest of its life! It’s no wonder that these crabs have such huge legs, right?

Japanese spider crabs are huge
Japanese Spider Crabs are huge / Source

7. They like cold water

It’s not really sure which temperature the Japanese Spider Crab prefers. They don’t seem to mind hotter water when the mating season starts.

It’s generally believed though, since they remain at a depth of around 300 meters (980 ft), that they prefer a temperature of about 10 °C (50 °F). Even though they can tolerate temperatures of about 6 to 16 °C (43 to 61 °F), they are usually held in aquariums at this temperature.

8. They are scavengers pur sang

If you look at a Japanese Spider Crab then you can’t help to think that they look kind of clumsy. These long legs surely don’t do them any good in terms of hunting for prey.

Their most favorite hobby is to scour the ocean floor to find the dead bodies of recently deceased animals and use their long legs to pick them apart.

9. The crab is in fact an omnivore

The fact that they like to feast away at the dead bodies of other sea creatures doesn’t mean they solely eat meat.

They also use their long legs to pick plants and algae that grow on the ocean floor. So yes, the Japanese Spider Crab isn’t picky at all when it comes to food!

10. Japanese Spider Crabs get very old

The diet they have must be very healthy because Japanese Spider Crabs can become as old as human beings.

Better yet, if they don’t get killed by a predator such as an octopus and die a natural death, the chances of them living longer than a century is much higher than for us!

11. They are considered a delicacy

Crabmeat tastes yummy, that’s a known fact. Is this any different for Japanese Spider Crabs?

No, they are considered a true delicacy in many parts of Japan!

The problem lies in the fact that overfishing has seriously lowered their population and measures have been taken to avoid the species to be extinct. One of them is that hunting for these crabs is prohibited in the Spring when they move to more shallow waters during the mating season.

12. It has been described as a “slow and stupid creature”

What has been described as an “ugly giant crab that lives off the coast of Japan,” used to be the extreme fear of Japanese fishermen. Whenever they had to dive to the bottom of the ocean, they feared that the giant crab would swallow them alive.

There is nothing to fear about however as they are pretty much incapable of harming a human being. Their long legs are only able to kill small sea creatures and their claws to open mussels or shells. Therefore, an issue in “Popular Science” dating from 1920 ironically called them a “Slow and stupid creature.”

Spider crabs in an aquarium
Japanese Spider Crabs in an aquarium / Source

More interesting facts about the Japanese Spider Crab

13. The scientific name of the Japanese spider crab is Macrocheira Kampfaeri. Machorcheira comes from two Greek words, first of all, Makros which means big or long, and Cheir which means hands or arms. So this essentially refers to its long legs.

14. Two fossil species belonging to the same family have been found, Macrocheira ginzanensis and Macrocheira yabei, both from the Miocene of Japan which lasted from around 23.03 to 5.333 million years ago.

15. While the Japanese Spider Crab has the longest leg span and is the biggest of all living arthropods, it is not the heaviest of them all. the heaviest arthropod is the American lobster and both of them are crustaceans.

16. The carapace of the Japanese Spider Crab is pear-shaped and ranges from dark-orange to light tan in color. Unlike some other species, the crab is unable to change in color.

17. The legs of the Japanese Spider Crab are not only very long but also very weak. A study has shown that nearly 3 quarters of these crabs are missing at least one limb. The cause is assumed to be either because they have been trapped in nets or because they were attacked by predators.

18. Japanese Spider Crabs seem to be very placid animals. This means that they aren’t easily excited and just go with the flow, which mostly means spending their days looking for food. their appearance is much more exciting than their daily life.

spider crab life
The Japanese Spider crab spends its days looking for food / Source

19. Most spider crabs use their legs to decorate themselves with shells or other objects that are lying around on the ocean floor. Adult Japanese Spider Crabs do not. Either they are too lazy, or they can’t find enough things lying around as they move deeper and deeper as they get older. Another reason is that they don’t need to camouflage themselves as they have very few enemies where they live.

20. You would assume that any creature living in the ocean can do it, but the opposite is true. Japanese Spider crabs actually can’t swim!

21. Japanese Spider Crabs just mind their own business. They spend their days looking for food and don’t have any interest in communicating with other crabs.

Japanese spider crab up close
Close-up of a Japanese Spider Crab / Source

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