The Biggest Crab in the World, Plus 8 Enormous Contenders

The Japanese spider crab (Macrocheira kaempferi) is no ordinary crab, but a massive arthropod inhabiting the waters around the Japanese islands.

Recognizable by its long, spindly legs spanning more than 13 feet (4 meters), it boasts a carapace up to 15 inches (37 cm) wide and can weigh 40 pounds (18 kg). Its body is typically adorned with algae and marine organisms, providing camouflage in its natural habitat.

Primarily nocturnal, Japanese spider crabs scavenge for mollusks, fish and detritus. They are generally solitary creatures, although they congregate in large numbers during the mating season. With meat that's sweet and tender in texture, Japanese spider crab is a prized delicacy in local cuisine.

The Tasmanian giant crab (Pseudocarcinus gigas) is an enormous crustacean that lives off the coast of Tasmania, Australia. Commercially fished for its prized meat, it can weigh over 20 pounds (9 kg), with a rounded carapace that measures 18 inches (46 cm) across. Its major claw can be up to 17 inches (43 cm) long.

Living and breeding in deep waters, the Tasmanian giant crab feeds on small fish, crustaceans and carrion. In doing so, it helps to control populations of prey species and plays an important role in nutrient cycling. This makes it crucial to keeping Tasmania’s underwater ecosystem in balance.

The coconut crab (Birgus latro) is the largest terrestrial arthropod in the world, living in the tropical regions of the Pacific and Indian Oceans, including islands like Christmas Island and the Seychelles.

Known for its surprising ability to climb coconut trees, the coconut crab can reach a leg span of about 40 inches (1 meter) from leg tip to leg tip and can weigh 10 pounds (4.5 kg). This makes it the largest land crab in the world.

Despite its name, the coconut crab is not solely reliant on coconuts and eats a varied diet, including fruits, nuts, small animals and carrion. It possesses a keen sense of smell and can crack open coconuts with its powerful claws. Incredibly strong, a single crab is capable of lifting 60 pounds (27 kg).

The Alaskan king crab (Paralithodes camtschaticus) is a large crustacean that people prize for its succulent meat. Native to the cold waters of the North Pacific, it primarily inhabits the Bering Sea and Gulf of Alaska.

Known for its distinctive spiky shell and long, spidery legs, it can have a leg span exceeding 5 feet (1.5 meters) and weigh up to 28 pounds (13 kg), making it one of the largest edible crabs.

Sometimes also called the red king crab, Alaskan king crabs are omnivorous scavengers, feeding on a variety of organisms including mollusks, fish and algae. Conservation efforts, including catch quotas and regulations to protect juvenile crabs, are in place to ensure sustainable fishing practices and maintain healthy crab populations.

The Dungeness crab (Cancer magister) is native to the West Coast of North America, ranging from Alaska to California. Culinary circles consider it a delicacy, valuing the crab for its delicious meat, which accounts for about one-fourth of its weight.

The Dungeness crab has an oval-shaped, spiny carapace, varying in color from brownish-red to purple or olive-green, with two large, asymmetrical claws. It typically has eight jointed legs and a relatively small abdomen.

Male Dungeness crabs are 7 to 9 inches wide (18 to 23 cm) and 4 to 5 inches (10 to 13 cm) long. They can weigh 1 to 3 pounds. These large crabs inhabit sandy or muddy bottoms in coastal waters and are opportunistic feeders, consuming a variety of prey, including clams, fish and other crabs.

The snow crab (Chionoecetes opilio) lives in the cold waters of the North Pacific and North Atlantic Oceans. Male crabs are larger than female crabs, measuring 6.5 inches across and weighing around 3 pounds (1.4 kg). Known for their delicate meat, snow crabs are highly sought after in the seafood industry.

You can recognize snow crabs by their spiky, oval-shaped carapace and long, slender legs covered in small spines. Their coloration ranges from light brown to reddish-orange. They inhabit deep-sea environments, typically living on sandy or muddy bottoms.

Snow crabs are opportunistic feeders, consuming a variety of small invertebrates, including mollusks, worms and tiny fish.

The giant mud crab (Scylla serrata) is a crab species native to the Indo-Pacific region, commonly living in mangrove forests, estuaries and shallow coastal waters.

This Indo-Pacific mud crab can have a carapace width of up to 11 inches (28 cm) and weigh over 11 pounds (5 kg). Its coloration varies from dark brown to greenish-gray.

Capable of growing to large sizes and known for its delicious meat, the giant mud crab is a prized catch in many Asian countries. They have a robust, oval-shaped carapace and powerful claws that they use for defense and capturing prey.

These crabs are omnivorous, feeding on a variety of prey, including small fish, mollusks, other crustaceans and ocean detritus.

The red rock crab (Cancer productus) inhabits the western coast of North America (all the way from Alaska to California, like the Dungeness crab).

It’s adaptable to various habitats, including rocky shores, tidal pools and eelgrass beds, where it feeds on a variety of prey, including other crustaceans and small fish. It has a typical carapace width of up to 6 inches (15 cm) and usually weighs no more than 4 pounds (1.8 kg).

Red rock crabs have a reddish-brown carapace with distinctive red or orange coloring on their claws and legs. This coloration serves as camouflage among rocky substrates, helping it to hunt and avoid predators.

The European spider crab (Maja squinado) is native to the eastern Atlantic Ocean and Mediterranean Sea. It features a spiny carapace — which can measure up to 7 inches (18 cm) in width — and long, slender legs. Its coloration varies from reddish-brown to orange or purplish-black, providing effective camouflage among seaweed and rocky substrates.

Although they’re omnivorous, these crabs feed primarily on dead animals. Commercial fisheries target this species for its succulent meat, which is particularly popular in Mediterranean cuisine.

Conservation efforts aim to ensure there are sustainable harvesting practices in place and protections from overexploitation.

This article was created in conjunction with AI technology, then was fact-checked and edited by a HowStuffWorks editor.