The Japanese spider crab is a huge crustacean that can reach up to 12.5 feet long and is usually found in the Pacific Ocean near Japan. They might seem like scary monsters from old movies, but they’re actually very calm creatures. People call them “spider crabs” because they look like big spiders.
These crabs usually live in holes and pits on the ocean floor, anywhere from 160 to 2,000 feet deep. Because they live so deep and have tough, spiky shells and big legs, not many animals try to eat them. They eat both dead things and plants they find on the ocean floor, but sometimes they’ll also eat fish if they happen to come close enough.
Japanese Spider Crab Classification
| Kingdom | Animalia |
|---|---|
| Phylum | Arthropoda |
| Class | Malacostraca |
| Order | Decapoda |
| Family | Inachidae |
| Genus | Macrocheira |
| Species Name | Macrocheira Kaempferi |
Japanese spider crabs haven’t been checked by the IUCN to see if they’re in danger, so they’re not officially considered endangered. But because people are catching too many of them and ruining where they live, their numbers are going down. People are working on ways to stop catching so many spider crabs to help keep them safe.
Can you explain what a Japanese spider crab is?
Japanese spider crabs are really big and can reach up to 12.5 feet long. They’re the largest kind of crustaceans, which are animals like crabs with hard outer shells. These crabs have 10 legs and are one of the biggest creatures without a backbone.
Where Japanese spider crabs live and what they look like.
Japanese spider crabs are found in the Pacific Ocean near Japan and Taiwan, living at depths ranging from 164 feet to 1,640 feet. They prefer temperatures around 50 degrees Fahrenheit. Their bodies are orange-and-white with cream-colored undersides, blending in with the ocean floor rocks. With round shells and long legs, they resemble spiders, hence their name. They also have spines near their short eye stalks. Male crabs are bigger than females, with larger legs holding their claws, while females have wider abdomens to carry eggs.
What Japanese spider crabs eat and how they act.
Japanese spider crabs move slowly and don’t hunt for food. Instead, they search for dead plants or animals to eat, but they might also catch and eat live fish or other small sea creatures. They belong to a group called decorator crabs, which decorate their shells with sponges or anemones to blend in with their surroundings. Young Japanese spider crabs do this, but adult ones don’t need to because they don’t have many predators where they live deep in the ocean.
How Japanese spider crabs reproduce.
During mating season, which runs from January to April, Japanese spider crabs move to shallower waters. Mating involves the male transferring sperm to the female internally by inserting a spermatophore. The female then carries fertilized eggs in her abdomen. Females can produce over a million tiny eggs, each about 0.03 inches in size. After hatching, which takes around 10 days, the young crabs receive no parental care and molt for the first time about nine to 12 days later. In captivity, researchers have observed that a single molt of a Japanese spider crab took 103 minutes, and they grow at a rate of almost 22 percent.
Gaint Japanese Spider Crab Facts
- Giant Leg-Span : Japanese spider crabs have the widest leg-span of all creatures with legs. Some can be wider than two grown men and their long legs are covered in small spikes.
- Males vs. Females : Males are usually bigger and have larger claws to defend themselves. Females have wider bodies to carry their eggs.
- Scavengers : These crabs prefer scavenging for dead animals or plants on the ocean floor rather than hunting for prey.
- Culinary Delicacy : In Japan, they’re considered a delicacy, especially the savory meat found in their long legs. Fishing is restricted during breeding season to protect their population.
- Decorator Crabs : They belong to a group of crabs called “decorator crabs” because they decorate their shells with sponges and plants to blend in with their environment.
- Regenerating Limbs : If their legs get torn off, they can regrow them during their molting cycle.
- Egg Layers : Female crabs can lay up to 1.5 million eggs at once, but only a few survive to hatch.
- Larval Stage : After hatching, they go through a transparent, legless larval stage before becoming adults.
- Size Limits : Their upper shells stop growing once they’re adults, but their legs keep growing.
- Molting Process : Like other crustaceans, they shed their shells to grow bigger.
- Female “Aprons” : Females carry their fertilized eggs in a special area called the “apron.”
- Mating Habits : They migrate to shallower waters during breeding season, which is between January and April.
- Gentle Giants : Despite their scary appearance, they’re calm and slow creatures that don’t hunt actively.
- Japanese Name : In Japanese, they’re called “taka-ashi-gani,” which means “long-legged crab.”
- Long Lifespan : They might live up to 100 years, making them one of the longest-lived crabs known.
Some people who have seen or worked with the Giant Spider Crab say they’re very gentle animals. But I’m not sure if I believe them. It could be a trick, maybe the crabs are planning something evil, like taking over the world. If you’re not scared of Giant Spider Crabs yet…
