Crabs are a type of crustacean belonging to the Brachyura family and are closely related to lobsters, shrimps, and prawns. The appearance of crabs varies significantly between species in terms of shape and size; however, most have a hard shell (carapace), pincers, and legs.
So how many legs do crabs have? Get to know more the facts as you continue reading this post.
Brief Evolutionary Background
Crabs are one of the most recognizable crustaceans, with their familiarly-shaped shells and omnivorous diets that allow them to thrive in both brackish and saltwater environments. With their ability to feed on a variety of flora or fauna, crabs have become one of the world’s most versatile species, easily adapting themselves to whatever environment they find themselves living in.
Dating back to 250 million years ago, crabs were one of the first creatures on Earth and evolved from lobsters. Their nourishment consists of invertebrates, mollusks, worms, as well as certain vegetation–which are in turn the sustenance of their natural predators such as larger crustaceans, fish, or birds.
Today, the world is host to a staggering 4,500 species of crabs; from kings and hermits to species that are adept at living out of water for extended periods. These crustaceans can be found in all kinds of habitats, ranging from tropical rainforests to icy polar regions. Though they must return occasionally to humidify their gills with water, some varieties have adapted incredibly well – allowing them to thrive both on land and in sea.
Crabs are an abundant species found across diverse habitats due to their prolific breeding and immense adaptability. In addition to being a nutritious food source for humans, they also act as prey for many other animals in the wild. Their specialized legs make them incredibly agile creatures that can effortlessly traverse different terrains with ease.
How Many Legs In Total
Crabs typically have ten legs – five pairs of walking legs for locomotion and three pairs of claws for grabbing food. The last pair of legs is modified to sense vibrations in the water or air, which helps them locate prey. These animals are known as decapods.
Most species of crabs have two distinct sets of claws, totaling eight legs. Their first four legs, or “pereiopods,” are designed for walking and usually have sizable pincers. The next pair, known as the “pleopods,” works best when swimming and filtering food particles from the water column. Lastly, their last set is located near their posterior area and functions mainly in aiding with grooming needs—trimming body parts that can’t be reached otherwise.
All in all, crabs possess ten legs. Many mistakenly refer to the first two (pereiopods) as “claws” due to their size and specialized function. Nonetheless, we can safely say that they have eight legs overall – even if others refer to them having “hands” instead of the correct number of limbs.
Are The Front Claws To Be Considered As Hands Or Legs
Crabs are sea creatures with a strong outer shell that shields their vulnerable innards. Although they have ten legs, many people ponder whether the front claws of crabs should be considered “hands” or limbs. Unfortunately, there is not one straightforward response to this query; instead, it is complicated.
For starters, crabs have eight legs; however, the two at the front are specifically adapted for gripping and handling food or objects. These claws are much larger than their other six feet, allowing them to move along the seabed.
While crabs do possess a total of eight appendages, one could argue that the first two should not be counted as “legs” due to their specific purpose. Essentially, these animals are equipped with two specialized pincers or “hands”, enabling them to maneuver and interact with their environment.
So in response to the question, “How many legs do crabs have?”, most would answer eight rather than ten. It is worth noting, however, that crabs possess a total of ten limbs, with two being specialized for gripping and handling food or objects. For this reason, some may refer to them as having hands instead of legs.
From Shortest To Longest Legs
Crab legs come in an array of shapes, sizes, and quantities. The smallest species of crab is the Pea Crab (Pinnotheres pisum) with impressive legs that measure only a few millimeters! This remarkable creature stands out from other crabs, not just because of its size but also due to the fact that it’s a parasite – rather than hunting for food, this tiny creature lives inside mussels’ gills and shells or any other bivalves.
On the opposite side of the scale are crabs like the Coconut Crab (Birgus latro), which possess an impressive ten pairs of legs! These remarkable arthropods can even climb trees for coconuts and other fruits, mirroring their namesake. Though the Japanese Spider Crab boasts the longest limbs out of all crab species, with measurements extending up to 4 meters (13 feet) from one leg tip to another, it still maintains twenty pairs just as other crabs do.
Are All Crabs Edible
While indulging in the deliciousness that is crab might be a popular pastime around the world, it’s important to understand which species of this crustacean are edible and safe for human consumption. Generally, most types can be eaten with no issues; however there are some exceptions like Mosaic Crab, Devil Crab (Toxic Reef Crab), and Shawl Crab. To ensure safety while enjoying your seafood feast, make sure you know exactly what type of crab you’re consuming.
The Mosaic Crab stands out among the sea population due to its eye-catching shades of cream and brown strewn across its carapace. Unfortunately, this species’ beauty comes at a price – it is highly toxic for humans if ingested or touched! This crab can mostly be found in Singaporean and Australian waters.
While the Devil Crab, or Toxic Reef Crab, is native to Southeast Asia and down into Australia and New Zealand, it is not recommended for consumption due to high levels of tetrodotoxin and saxitoxin poisoning.
The Shawl Crab, a diminutive species of crab native to the shallow waters of the Indo-Pacific region and Australia, is not suitable for human consumption due to its petite size and unpleasant smell.
To sum up, crabs have a total of ten legs; some may contest that the front two should not be counted. Moreover, it is critical to know which type of crab is edible before consuming one, as not all species are safe for eating. Lastly, crab legs come in various shapes and sizes; the Coconut Crab has an extraordinary ten pairs of bulky legs.