The 10 Largest Crabs in the World

There are over 6,000 species of crab inhabiting the world. Crabs are decapods, which also include lobsters, shrimps, and prawns. These invertebrates belong to the family of Brachyura and are covered in a hard shell to protect their body, have ten legs, and two claws. In oceans, on land, and in freshwater crabs stretch their presence all over the world. They are eaten by various aquatic life and enjoyed as a delicacy in many cultures.

On this list, we will take a look at ten of the largest species of crab in the world. The size of each crab varies and some can grow to be unusually large. The crabs on this list are ranked by what species gets the largest, based on their carapace width and mass.  Let’s take a look at the ten largest crabs lurking in the waters.

#10:Florida Stone Crab

The Florida stone crab (Menippe mercenaria) is one of the most expensive species in the world and only their claws are eaten. Their carapace is 5 to 6.5 inches, but their claws are large and harvested for eating. Females are larger than males but males generally have larger claws. The stone’s crabs’ claws can reach up to 5 inches. These crabs are captured then released back into the ocean after their claws are harvested.

Stones crabs can be found in the western North Atlantic Ocean. In South Carolina and Georgia, they inhabit salt marshes. They dig holes 6 inches to 3 feet deep near semi shallow water. Along with humans, other predators included turtles, octopi, and cobia.

#9: Blue Crab

Blue crabs (Callinectes sapidus) are also called the Atlantic blue crab, and the Chesapeake blue crab. They are olive green and most know for their bright blue claws. This species can reach up to 9 inches but will only weigh up to 1 lb. Found in the Atlantic ocean and through the Gulf of Mexico, this species is widespread and has been introduced to other parts of the world for its meat.

Blue crabs feed on clams, oysters small fish, and decaying animals. With a lifespan of three years, they spend their time bottom-dwelling in shallow waters. In winter they bury themselves to survive the colder temperatures. Blue crabs handle global warming better than other species as they breed in warmer temperatures and have a hard time in cold waters.

#8: Opilio Crab

The opilio crab (Chionoecetes opilio) is a species of snow crab, also known as opies. They live in the northwest Atlantic Ocean and the North Pacific Ocean. Male crabs are larger than females for this species and can grow up to 6.5 inches and will weigh up to 3 pounds. These crabs are found at depths of 43 to 7,175 feet.

The opilio crab eats small invertebrates and scavenges at the bottom of the seafloor. They usually live for 5 to 6 years and mate before they die. Snow crabs are caught near Alaska and Canada, then are sold across the world.

#7: Dungeness Crab

The Dungeness crab (Metacarcinus magister) is found in the west coast oceans of North America. On average they reach around 7.9 inches but large ones may reach up to 9.8 inches. This crab is the most fished species in the Pacific Northwest. These crabs are found at depths of 43 to 7,175 feet.

The Dungeness crab is more expensive than other crabs eaten because of its large shell and a small amount of meat. They periodically molt their shell in fall before mating occurs.  Males get attracted to females by the pheromones in their urine.

#6: Brown Crab

Brown crabs (Cancer pagurus) are also called edible crabs. Females are larger than males and can grow up to 6 inches but in the right habitat, they can reach 10 inches. They are found in the northeast Atlantic waters and can reach waters near Norway and Africa. They live at depths of up to 330ft.

Brown crabs inhabit holes, hide under rocks and other debris. They are nocturnal and come out to feed at night. During the day they bury themselves but never sleep. They stay awake and watch for enemies. Octopus are their main predator but this crab is fished and frequently farmed.

#5: Red King Crab

The red king crab (Paralithodes camtschaticus) is also named Kamchatka crab and the Alaskan King Crab. The red king crab is the largest species of king crab with a caprice of 7 inches and a mass of 6 lbs. They are capable of having their carapace reach 11 inches and can weigh as much as 28 lbs but that is rare. Red king crabs are named after the color they turn when cooked but can be brownish to blueish red and are covered in sharp spikes.

Red king crabs are endemic to the Bering Sea, North Pacific Ocean, and near the Kamchatka Peninsula. In the minds of many, this species is the prime choice of crab and is harvested across the oceans they live in. The decline of their population in the wild has been steadily happening. Overfishing, a large number of predators, and global warming are some theories as to why this crab is becoming rarer.

#4: Giant Mud Crab

The giant mud crab (Scylla serrata) is also known as the Mangrove crab, black crab,serrated swimming crab, and the Indo-Pacific mud crab. The average carapace of this species is 9 inches but they can get as large as 11 inches and up to 11 lbs. They are found in estuaries and mangroves across the Indo-Pacific.

Mud crabs range from green to black and have spikes on the edge of their carapace. Mollusks and crustaceans are their main source of food but they will also eat plants and fish. Female mud crabs will bury themselves in the mud and males seek shelter in a burrow. In cold temperatures, they begin to become inactive.

#3: Coconut Crab

Coconut crabs (Birgus latro), also called robber crabs are the largest terrestrial crabs. They can grow up to 3 ft 3 in and weigh 9 lbs. In areas with human populations, their presence has been extirpated but they are found on islands across the Indian and Pacific Oceans. The coconut crab is unable to swim and spends most of its life on land.

The coconut crabs’ closest relative is the hermit crab, but they have evolved to be gigantic. They have the strongest claws of all land-dwelling crustaceans and can produce up to 3300 Newtons of force. As larvae, they live in the sea for around a month then travel onto land. Young coconut crabs will live in snail shells until they grow too large. When large enough they will take shelter in underground burrows next to coconut trees. They have a long life span of over 60 years and survive off small animals, fruits, nuts vegetation, and carrion.

#2: Tasmanian Giant Crab

The Tasmanian Giant Crab (Pseudocarcinus genus) is one of the largest crabs in the world with a carapace width up to 18 inches and a mass of up to 39 pounds. This giant lives in muddy bottoms off in the Southern Australian Ocean on the edge of the continental shelf. They are most common at depths of 560 to 590 ft in the summer and will travel deeper into the water in the winter at a depth of 620 to 1,310 ft.

The Tasmanian giant crab eats smaller slow-moving species like gastropods, crustaceans, and starfish. They will also feed on carrion which is the dead and decaying flesh of past life. Male Tasmania crabs reach twice the size of females. The average for males is over 30 lbs and the female average is 15lbs. Males can reach up to 39lbs and have one oversized claw. The top of their carapace is red with a yellow or light-colored belly.

#1: Japanese Spider Crab

The Japanese spider crab is the largest crab in the world. Living near Japan, the Japanese spider crab (Macrocheira kaempferi) has the longest legs of any anthropod. From claw to claw their legs span measures around 12 ft. They have a carapace width of 16 inches and can weigh up to 42 lbs. Around the Japanese islands of Hanshu, to Tokyo bay, this gentle giant can be found at depths of 160 to 1,970 feet.

Pearl shaped with a narrow head, the Japanese spider crab is orange covered in dark spots. To avoid predators they will rub algae and sponges to camouflage better in the ocean. Large fish and octopus are their most common predators along with humans. Actions have been taken to ensure this species population does not decline from overfishing. A diet of decaying matter on the seafloor helps this species live up to 100 years.