Spider Crab: 15 Facts You Won’t Believe!

Japanese spider crab facts about the species with a strong ability to camouflage.

Spider crabs belong to the Macrocheira genus. The scientific name of spider crabs is Macrocheira kaempferi. Spider crabs are located in Japan so they are also known as Japanese spider crabs. A spider crab belongs to class Malacostraca, family Inachidae, and genus Macrocheira. Spider crabs are known as the tallest crabs among spider crabs. The Japanese spider crab resembles spiders and is found at depths of 2500 ft (762 m) in oceanic waters. The Japanese name for spider crab is 'taka-Ashi-gani'.

Spider crabs have a thick shell-type skin with small spines and tubercles. These spiny tubercles also cover the carapace, which in turn blends with the ocean floor, highlighting their ability to camouflage. Here are some interesting spider crab facts for your perusal, afterward do check our other articles on king crabs and blue king crabs as well.

Spider Crab

Fact File

What do they prey on?

Dead Animals, Shellfish

What do they eat?


Average litter size?

1.5 Million Eggs Per Season

How much do they weigh?

41.8-44.2 lb (18.96-20.04 kg)

How long are they?

40-80 in (101.6-203.2 cm)

How tall are they?

Leg size: 30 in (76.2 cm)

What do they look like?

Orange, Whites Spots

Skin Type

Shell, Tubercles, Spines

What are their main threats?

Octopus, Large Fish, Humans

What is their conservation status?

Not Listed

Where you'll find them



Pacific Ocean, Southern Japanese Islands





Scientific Name

Macrocheira kaempferi





Spider Crab Interesting Facts

What type of animal are spider crabs?

The Japanese spider crab (macrocheira kaempferi) has the longest legs in the spider crab family. The Japanese spider crab has ferocious and untamed looks, but they are gentle. They crawl fast as they have long legs.

What class of animal do spider crabs belong to?

The Japanese spider crab belongs to class Malacostraca, family Inachidae, and genus Macrocheira. This species of Japanese spider crabs are known for their resemblance to spiders.

How many spider crabs are there in the world?

The Japanese spider crab is on the list of conservation animals of Japan. The Japanese government made a law not to fish any spider crab from January to April. They are currently endangered due to overfishing.

Where do spider crabs live?

Spider crabs live in the ocean at depths of up to 2500 ft (762 m). This species of spider crabs live mostly in the Pacific Ocean and the southern islands of Japan. As spider crabs are commonly found in and around Japan, they are also called Japanese spider crabs.

What is a spider crab's habitat?

A Spider crab's habitat is in the Southern islands of Japan and the Pacific Ocean near Japan. They live at a temperature of 10 degrees Celsius.

Who do spider crabs live with?

The Japanese spider crab lives on its own. Both male and female spider crabs live on their own in the depths of the ocean.

How long do spider crabs live?

The average lifespan of a Japanese spider crab is 100 years. Japanese spider crabs can live up to 100 years. A spider crab can live with the help of its shell and long legs which allow them to escape from predators.

How do they reproduce?

During the mating period, crabs will go further deep into the ocean waters. The male and female crabs push each other with their lower abdomen in order to copulate and reproduce. Female spider crabs can lay 1.5 million eggs per season.

What is their conservation status?

Spider crab’s conservation status has not been listed by IUCN as this species resides in deep oceanic waters and is hence difficult to study. Overfishing is the main reason for the decrease in the spider crab's population.

Spider Crab Fun Facts

What do spider crabs look like?

Spider crabs use their camouflage ability to protect themselves from predators.

They look like spiders, as their name suggests, with long legs and round shells. Their body is orange in color and they have white spots on their legs. They are the largest crabs in the arthropods class. Another giant spider crab fact is that their legs are the longest at 30 in (76.2 cm). The crab has a bumpy carapace which helps it blend in with the rocky ocean floor, rendering its ability to camouflage that protects the animal from other predators. Sometimes, these sluggish creatures cover their shells with zoophytes and seaweeds. In males, the limbs with claws tend to become longer as compared to other limbs.

How cute are they?

Japanese spider crabs may look untamed but are gentle, which makes them cute. The white spots on their body and their orange color are beautiful to see. They are even raised in aquariums.

How do they communicate?

The Japanese spider crab is known to be alone and lives on its own. However, they do communicate through their organs with others of their species. They can communicate with others based on their needs, for example, warning of predators or during the breeding season. Male and female crabs can also communicate with each other through pheromones.

How big are spider crabs?

Japanese spider crabs are known as the longest crabs in the entire crab family. Spider crabs are 10 times bigger than a normal crab. Their leg span can extend up to 30 in (76.2 cm) and their size can range between 40-80 in (101.6-203.2 cm).

How fast can spider crabs run?

Spider crabs generally move slowly, although can move faster as they have long legs on their body. They crawl and move faster than other crabs. Spider crabs are the most advanced crabs in the entire crab family.

How much do spider crabs weigh?

A Japanese spider crab weighs around 41.8-44.2 lb (18.96-20.04 kg). They are known as the largest and longest crabs in the entire crab family.

What are the male and female names of the species?

There are no sex-specific names for male and female spider crabs.

What would you call a baby spider crab?

Spider crabs are known for their resemblance to spiders. A baby spider crab is called an offspring.

What do they eat?

For feeding, the Japanese spider crab has in its diet algae, plants, shellfish, and carrion (dead animals). They usually don’t hunt as they are omnivorous, and prefer to find their food, whether plant or animal matter. They are able to find everything in their diet easily in the ocean. These crabs use their huge claws to pry open shellfish and consume them as part of their diet.

Are they eaten by humans?

Yes, they are eaten by humans. Humans prefer them as they think that their taste is remarkable.

Would they make a good pet?

Yes, if you are an animal lover. Researchers have said that you can keep a Japanese spider crab in an aquarium as a pet. They will need a properly functioning, large aquarium to accommodate their needs. Feeding them algae, plants or shellfish is not difficult.  

Did you know...

Spider crabs are from marine crabs. Japanese spider crabs are considered the largest crabs and the most delicious crabs. In research, it is proven that they don’t usually hunt unless it is necessary. Male spider crabs are larger than female spider crabs. They send pheromones as a signal for mating.

Different types of spider crab

There are over 60,000 species of spider crabs in the world. Japanese spider crabs are the largest and longest among them. They are found in the depths of the ocean waters.

Do people eat spider crabs?

Yes, spider crabs have high demand in the seafood market. They are found in oceans and are sold in markets. The giant spider crab is deliciou, soft, and juicy.

Here at Kidadl, we have carefully created lots of interesting family-friendly animal facts for everyone to discover! Learn more about some other arthropods including green crab facts, or Sally Lightfoot crab facts.

You can even occupy yourself at home by coloring in one of our free printable Spider crab coloring pages.



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