Crabs are considered decapods, and this categorization includes familiar marine life such as shrimps, prawns, and lobsters. There are over 5,000 species of crab in the world.
They have claws with ten legs, and are covered in a hard shell to protect their bodies. Crabs are ubiquitous creatures that you can find on the land and in the sea in many parts of the world.
They are also a delicacy in various cultures. We’ve taken the liberty of compiling a list of 10 large crabs, from biggest to smallest.
Even on this list, there can be a sizable difference between the first and tenth-largest crabs in the world, and it will all be based on their mass and carapace width. Continue reading to see the ten biggest crabs ranked worldwide.
Table of Contents
Japanese Spider Crab
The largest crab in the world is the Japanese spider crab (Macrocheira kaempferi). The crab’s body can potentially grow up to 16 inches (carapace width), and the entire crab can weigh a stunning 42 pounds.
The Japanese spider crab is second only to the American lobster when it comes to sheer mass. It is extremely armed thanks to its exoskeleton, which protects it from natural predators such as octopus, and it serves as an effective form of camouflage.
This larger-than-life spider has the greatest leg span of any arthropod, and from claw to claw, it can reach up to 12.1 feet in length.
Moreover, it has a noticeably narrow head, it’s orange, and dark spots all over. This crab inhabits the waters around the Japanese islands of Hanshu, and they can be found at depths of 160 to 1,970 feet.
As it pertains to camouflage, its bumpy carapace is perfect for blending in with the rocky seafloor. What’s more, spider crabs will cover its shell with sponges and other kinds of animals to enhance their level of deception.
This crab feasts on decaying matter at the bottom of the ocean floor, and this species, in particular, can live up to 100 years.
There are measures to make sure that the Japanese spider and its population do not suffer from too much fishing.
Tasmanian Giant Crab
The Tasmanian giant crab (Pseudocarcinus genus) is usually found at depths approximately 560 to 590 feet in the muddy bottoms off in the Southern Australian Ocean right on the edge of the continental shelf during the summer.
These crabs tend to travel to further depths of 620 to 1,310 feet during the winter. This giant crab’s diet consists of slow-moving gastropods the likes of starfish and crustaceans.
They are also known to eat carrion—the flesh of animals that are already deceased. The giant crab is considered to be among the largest crabs on earth.
It can reach an astounding mass of 39 pounds and a carapace width of up to 18 inches. Interestingly, the female Tasmania crabs only reach half the size of the males.
Moreover, the average mass for males is more than 30 pounds, while the females will only reach up to an average of 15 pounds. The top of their carapace is red, and they can have a light or yellow-colored belly.
Coconut crabs (Birgus latro) or robber class are the largest of the terrestrial crabs. The closest relative of the coconut crab is the hermit crab; however, they’ve evolved to be gigantic.
Furthermore, they are armed with the strongest claws of all crustaceans, which dwell on the land delivering a force of 3300 Newtons of force.
When they are in their larval stage of development, they’ll live in the sea for about a month before traveling onto the land.
This crab species lives on the Batanes islands, located in the Philippines. These crabs can weigh up to nine lbs and grow up to three feet three inches.
In areas populated by humans, their presence has been eliminated; however, they are found on Islands across the Pacific and Indian Oceans.
Coconut crabs are incapable of swimming and therefore spend most of their life on land.
When coconut crabs are young, they’ll live inside the shells of snails until they grow to be too large. Once they are too large, they’ll make homes underground burrows, usually right beside coconut trees.
These crabs can live up to 60 years, and their diet consists mostly of nut vegetation, small animals, carrion, and fruits.
Giant Mud Crab
The giant mud crab (Scylla Serrata), also called the Mangrove crab, Indo-Pacific mud crab, black crab, and other names. The mud crab belongs to the Portunidae family.
Their two hind legs are flattened and positioned for swimming. As large crabs, they have broad carapaces and have large claws that they use effectively to cut and crush prey.
For the most part, these crabs are mottled green or dark brown.
The giant mud crab has an average carapace of nine inches and has the potential to reach up to 11 pounds. They are commonly found in mangroves and estuaries along the Indo-Pacific.
Mud crabs’ main source of nourishment consists of crustaceans and mollusks. They will eat fish and plants as well.
Females will bury themselves in mud, and the males will seek shelter in the caves. When the temperature drops, the crabs become inactive.
Red King Crab
This crab happens to be the crab that comes to mind when it comes to cuisine, and as a result, they are targeted and harvested across the seas that they inhabit.
Their population has steadily declined due to overfishing, global warming, and their natural predators.
The red king crab is, in fact, the largest species of king crab, with a mass of six lbs and a carapace of seven inches.
These crabs have the potential to reach up to 28 pounds, and their carapace can reach eleven inches.
These crabs are named so because of the color they turn when cooked, but in the wild, they can be blue-ish or brownish-red and fully covered in sharp spikes.
The brown crab (Cancer Pagurus) is one of the more popular edible crabs. Brown crabs are known to live within the North Atlantic Ocean, the North Sea, and the Mediterranean Sea, as deep as 330 feet.
This species has a vibrant reddish-copper color, with an oval carapace that resembles a pie crust around the edges.
The brown crab has black tips on its claws. The female crabs are generally larger than the male crabs and can get as tall as ten inches in a suitable habitat, but they normally hover around six inches, seven pounds.
Brown crabs hide beneath rocks and inside holes and under and around debris. They feed at night since they are nocturnal, often choosing smaller crabs, echinoderms, and mollusks.
Instead, they bury themselves during the day and stay awake to keep an eye on predators. The brown crab can actually outlive many humans!
They are known to pinch their claws very hard when they feel threatened, so while they don’t usually just attack, they have quite the grip if you get too close.
Dungeness crab (Metacarcinus magister) is the most fished species that anglers target near the western coast oceans in the Pacific Northwest, in North America.
These crabs prefer a muddy or sandy habitat near river mouths that empty close to the ocean. The top of their shell is a purplish-brown color, and it is cream-colored underneath.
You can find the Dungeness crab anywhere from a mere 43 feet all the way to 7,175 feet. They get nearly ten inches tall and weigh between one and a half to three pounds.
Their body is broad and oval-shaped, hard shell. They have four legs that they walk on and two claws. They mostly eat other crabs, fish, starfish, squids, worms, and anything else with meat.
Their predators are octopuses, sea otters, humans, and the Pacific halibut. Compared to the brown crab and other edible crabs, the Dungeness crab is costlier because the amount of meat is small in relation to the large size of the shell. You can only eat a few ounces, which drives the price up for this popular delicacy.
This is another well-known edible crab that gets caught near Canada and Russia and then sold worldwide. They are typically brownish to bright red on the top and white or yellow underneath.
The male opies are typically larger than females, and they can get as big as six and a half inches, weighing up to three pounds. Their habitat depth is 164 to 820 feet, depending on which ocean zone they’re in.
The Opilio crab usually eats whatever is at the bottom of the ocean floor, such as shrimp, fish, worms, small invertebrates, sea urchins, etc.
Humans, halibut, seals, squids, larger crabs, and other types of fish are their enemies. They die after mating, which usually takes five to six years after they’re born.
Blue crabs (Callinectes sapidus), also known as the Chesapeake blue crab and the Atlantic blue crab, are most notable for having an olive green complexion with bright blue claws.
While they can get up to nine inches, they’ll weigh little more than one pound. These blue crabs are usually found throughout the Gulf of Mexico and the Atlantic Ocean.
However, they have now ventured to other areas of the world because of fishing and selling. Blue crabs eat oysters, small fish, clams, and other animals that are decaying.
They only live around three years, and they inhabit shallow waters for most of that time, burying themselves for warmth during the winter.
They breed in warm temperatures and often struggle during colder months. They also grow faster or slower based on the surrounding temperatures.
For example, blue crabs in the Gulf of Mexico grow quicker than their counterparts in colder waters and may reach maturity within just one year.
Florida Stone Crab
If you’re familiar with rare crabs, then you know the Florida stone crab (Menippe mercenaria) is not only edible, but they are some of the most expensive crabs in the world.
However, you can only eat their claws, so when an angler catches the crabs, they have to release them back into the ocean after the claws have gotten harvested.
The female crabs are larger than males, and in general, the Florida stone crab has a carapace that’s five to six inches, with claws getting as long as five inches themselves.
They usually only weigh around three to five ounces. You can find this crab species in salt marshes and the western North Atlantic Ocean.