Crabs are a type of crayfish with short tails. Their Latin name is brachyura. In nature, they have existed since the time of the dinosaurs.
Watching them walking along the beach, it’s hard not to wonder: “Why do crabs go sideways?” It looks, of course, very funny, but why don't they go, for example, forward or backward?
Mention in folklore
About why crabs go sideways, an old legend has been preserved. She says that the cancer with its cousin walked in the retinue of the sea lord, who was making a detour of his lands. And then suddenly a big shark blocked their path. Cancer bounced back in fear, and the crab slowly, moving sideways, took refuge in nearby algae. In punishment, Vladyka ordered the first to back off his whole life, and the second - to walk sideways.
It follows from this that this issue has been of interest to people for a long time.
Structural Features and Habitat
A small crab head smoothly passes into a rounded and flat body (abdomen), fitted under a powerful jaw-chest. The extremities (two pairs) of the male, located parallel to the abdomen, evolved into a copulative organ, and the females (four) - into a sac for carrying eggs.
Their habitat is freshwater natural reservoirs, seas and coasts. One of the species of these crustaceans, which lives near the Japanese islands, has a limb span of 3.8 meters, with a mass of 19 kg. This is the largest of the crabs.
These crustaceans spend most of their lives in shallow water, so nature rewarded them with specially adapted limbs. They have a dozen strong, long legs, whose knees look sideways. With rapid movement, the joints rise above the body. This structure of the limbs helps the crab to quickly hide in case of danger, buried in the sand. But why do crabs go sideways?
The thing is that with such limbs, it is possible to move quickly only with an extra step, which is what they, in fact, do in case of general anxiety. But if the crab calmly walks along the coast, you can see that it is moving forward. His eyes are located on special horns, on the crown, which allows the crab to inspect the territory within a radius of 360 °.
In addition, the claws of these crustaceans are not symmetrical, and they are both right-handed and left-handed. They can eat with one “hand”, and with the second in case of need to defend themselves, and during the flight the crab is covered by one of them as if with a shield. That is why all crabs go sideways.
Cancer performs the moonwalk
Of course, this crab relative can also walk around in any direction, but having sensed danger, he will necessarily back off. When moving in shallow water (back to front), the tail of the animal bends under the abdomen, scooping up a trickle of water, which accelerates its steps.
By the way, he also has to swim backwards, since on the tail side the cancer body is more streamlined, and claws do not interfere with it, but help.
Why do crabs on the beaches go sideways
Without a doubt, they can walk forward, slowly exposing one leg at a time, but you can’t go far in such a crowded place. Given that the crab's limbs do not look down, but to the sides, and its body is flat, moving sideways, it can develop a speed sufficient to save both predators and people.
All these reasons answer the question: “Why do crabs go sideways?”