Last updated on June 6th, 2023 at 11:13 pm
How many legs do crabs have? Crabs are crustaceans with 10 legs. However, they are often seen with only 8 legs because two of their legs are modified into claws. So, how many legs do crabs have? The answer is 10.
What Are Crab Claws For?
Crab claws are used for defense and offense. The large crab claw is used to ward off predators and the smaller one is used to capture prey.
Do All Crabs Have Claws?
No, not all crabs have claws. There are some species of crabs that don’t have claws at all. Instead, they have long, thin legs that they use to catch prey.
Several species exhibit claws of different sizes.
Species Of Crabs
There are over 4,500 species of crabs that have been identified. They come in all shapes and sizes, and can be found in every ocean on Earth. Some of the most popular types of crabs include king crabs, hermit crabs, snow crabs, and blue crabs.
King crabs have the largest legs in comparison to their bodies. These crabs are also called stone crabs or rock crabs. They are found in the warm waters of the Pacific and Indian Oceans. The king crab’s two large claws can grow up to a foot long.
The right claw of king crabs is usually much larger than the left claw.
Hermit crabs have asymmetrical abdomens that are soft and vulnerable. They use the discarded shells of other animals to protect their abdomens. Hermit crabs are found in all the world’s oceans.
Snow crabs are found in the cold waters of the North Pacific and North Atlantic oceans. They get their name from their snowy white legs. Snow crabs have long, thin legs with small claws.
Blue crabs are found in the warm waters of the Atlantic and Gulf coasts of North America. These crabs get their name from the blue color of their shells. Blue crabs have large claws and long, spindly legs.
How Do Crabs Walk?
Crabs walk sideways because of the way their legs are arranged. Their first two pairs of legs are shorter than the rest, and they are positioned closer to the crab’s head. This gives the crab a sideways gait.
Unlike humans, whose legs are attached to the hip and allow for straight forward or backward movement, crab legs extend out and to the sides of their bodies, with their joints allowing them to bend in a way that favors sideways movement.
This anatomy allows crabs to take advantage of the lever-like function of their legs, leading to more efficient and quicker movement in the sideways direction. Moreover, their robust exoskeleton also aids in providing stability during these lateral movements.
Crabs That Don’t Walk Sideways
While the sideways motion is indeed common, not all crabs walk this way. Certain species, like the forward-walking crab (Libinia emarginata), have evolved to walk straight ahead, similar to humans. Another notable species, the land crab (Cardisoma guanhumi), also primarily moves forward, especially when it’s covering long distances. These exceptions, however, are comparatively rare in the vast array of crab species found worldwide.
Advantages of Walking Sideways
Sideways movement affords several advantages to crabs. Firstly, the sideways movement is faster for crabs due to their unique leg structure. This increased speed can be crucial in escaping predators or catching prey.
Another benefit relates to the defensive capabilities of crabs. Many species have one claw larger than the other, which is used both for defense and attracting mates. By moving sideways, these crabs can keep their larger, more threatening claw facing towards potential threats.
Lastly, the sideways movement allows crabs to slip easily into narrow crevices and between rocks – crucial for avoiding predators and finding food in their typical coastal habitats.
Disadvantages of Walking Sideways
While the sideways movement offers various advantages, it also has its drawbacks. The primary disadvantage lies in visibility. Forward movement typically allows a wider field of vision, especially for creatures with forward-facing eyes. Crabs, however, have eyes on stalks which somewhat compensates for this, as they can move their eyes independently and look in different directions simultaneously.
Additionally, moving sideways may not be as efficient in terms of energy use as moving forward, especially over longer distances. This is one of the reasons why some species of land-dwelling crabs have adapted to walk forward.
Do All Crabs Live In The Ocean?
No, not all crabs live in the ocean. There are also land crabs and freshwater crabs. Land crabs are found in tropical and subtropical regions around the world. Freshwater crabs are found in freshwater rivers and streams.
Consumption of Crabs
Crabs are a favorite food all over the world. People love their juicy meat in many dishes. Some crabs are eaten completely, like soft-shell crabs. Others, we only eat certain parts, like the legs of the king crab. The way we eat crabs can tell us a lot about different food traditions.
Soft-Shell Crabs: Eating the Whole Thing
Soft-shell crabs are crabs eaten when their shells are still soft, usually just after they shed their old shell. You can eat the whole crab, shell and all. People often fry or sauté these crabs. When you bite into them, you get a nice crunch and then the soft crab meat. This kind of dish is common in America, Japan, and Thailand. In Japan, there’s a dish called ‘Soft-Shell Crab Tempura’ that’s very tasty.
King Crabs: Only the Legs, Please
On the other hand, with some types of crab, we only eat certain parts. For example, we usually eat just the legs of the Alaskan king crab. These crabs have a hard shell, so the rest of the crab isn’t easy to eat. But the legs are full of sweet, juicy meat. People often steam or boil the legs and serve them with melted butter. King crab legs are often found at fancy seafood buffets and are considered a special treat.
What It All Means
Eating crabs, whether whole or just parts, has a lot to do with tradition and health. Eating a whole soft-shell crab gives you extra calcium and other minerals. Eating only the legs of a king crab reduces waste because we don’t throw away as much.
Different ways of eating crabs can also tell us about different cultures. For example, people in the Chesapeake Bay area in America have been eating soft-shell crabs since Native American times.