Meet the Japanese spider crab, the largest arthropod in the ocean, with its impressive size and gentle nature making it a fascinating creature to learn about.
The Japanese ‘spider crab’ is a fascinating and impressive animal that is native to Japan‘s coastal waters. It is the largest arthropod in the ocean, with its long, spindly legs and armored exoskeleton making it look like something out of a sci-fi movie.
The Japanese spider crab (Macrocheira kaempferi) is a species of crab found in the waters around Japan.
It can grow up to 12 feet (3.6 meters) from claw to claw, making it one of the largest arthropods on Earth.
They inhabit depths of up to 1,000 feet and feed on small fish, shellfish, and algae.
The Japanese spider crab is a prized delicacy in Japan, particularly during special occasions.
It takes around 20-30 years for them to mature, making conservation efforts crucial to maintain their population.
Despite its intimidating size, the Japanese ‘giant spider crab’ is not an aggressive predator. Instead, it primarily feeds on dead animals, plant matter, mollusks, and other crustaceans. Its large size helps it avoid many predators, but it still relies on camouflage to blend into the ocean floor.
The chelipeds (the legs with claws) on the males of the species can stretch over 12 feet (3.7 meters) from claw to claw, while the walking legs are relatively smaller, although still big by crab standards. Interestingly, on female specimens, the chelipeds are shorter than the rest of the legs.
The female Japanese spider crab (Macrocheira kaempferi) is a rare and elusive creature.
Reaching up to 12 feet in leg span, they are the largest arthropod on record.
Female crabs have a slightly shorter leg span than males but are more massive in body size.
They are found in deep waters off the coast of Japan and are prized for their succulent flesh.
However, due to overfishing, female Japanese spider crabs are extremely rare, making sightings a significant event in marine biology.
Only about 100 females have been documented since records began.
Japanese spider crabs start life as fertilized eggs attached to their mother’s rear legs. After they hatch, they become tiny planktonic larvae drifting in the ocean. These larvae are extremely vulnerable to predators and ocean currents. As they grow, they undergo multiple molting stages, shedding their old carapaces (their hard protective shells) to make room for their expanding bodies.
Juvenile spider crabs look quite different from their giant adult forms. Younger crabs have shorter legs and a more compact body, making them resemble other crabs more closely. It’s only when the crab reaches adulthood that it develops its iconic long legs and massive size.
These animals are often scavengers, meaning they help clean the ocean by consuming dead animals and aquatic plants. They also use their strong claws to pry open shells and catch shrimp, mollusks, and other small ocean creatures. This diet plays an important role in maintaining the health of marine ecosystems.
Japanese spider crabs are known to scavenge for food, particularly in coastal areas where they live.
They feed on decaying organic matter, including dead fish and other marine animals.
These crabs have been observed digging into the sediment with their powerful claws to uncover buried prey.
In fact, a significant portion of their diet consists of scavenged food, which is essential for their survival in nutrient-poor environments.
If you’re interested in seeing a giant Japanese spider crab up close, you don’t have to dive into the ocean. Many aquariums house these incredible crustaceans in exhibits where visitors can learn more about their biology, behavior, and role in the ocean ecosystem.
- howstuffworks.com | Japanese Spider Crab: Enormous and Harmless to Humans
