Do all crabs walk sideways?

Crabs have a variety of body shapes and shapes, such as round, square, plough and fusiform. The crab body is divided into three parts: cephalothorax, abdomen and appendages. The cephalothorax is particularly developed, and the back is covered with a whole piece of cephalothorax, which has different shapes and great variations.

The cephalothorax is usually divided into several zones according to the position of the internal organs located under it, and the surface has various structures such as spines, grooves, slits, and protrusions, and the edges are mostly toothed, and the number of teeth varies from species to species. These partitions, surface structures and teeth are the basis for classification. The cephalothorax is folded ventral to meet the ventral surface at the front of the body.

The abdominal carapace is divided into 7 segments, usually the 1st to 3rd segments are healed, and the 4th to 7th segments are distinct. The abdomen of the crab is flattened, vestigial, and folded on the ventral surface of the cephalothorax, commonly known as the crab navel. Each of the two frontal margins has a stalked compound eye that can be rotated, which usually lies upside down in the eye socket and sticks out upright when moving.

The first antennae is located near the frontal margin and has a balancing capsule at the base; The second antennae are small and located on the inside of both eyes, and their base is the excretory organ. The appendages in the oral cavity are large jaws and small jaws, which together with the 1st to 3rd jaws form the mouthparts, and the shape of the mouth frame and the shape of the 3rd jawfoot are important taxonomic basis in some taxa.

Another peculiar function of the crab is that, in addition to the mouth and the tip of the crab claw, the other 8 "legs" have the ability to "distinguish taste". In 1930, biologists put a crab on blotting paper, and the gravy was sucked in in several places on the paper, and the last pair of "legs" of the crab touched the gravy, and immediately grabbed it and began to bite. After years of observation and research on an Australian sand bubble crab, scientists have found that the membranous disc on the basal ganglia of its foot was previously thought by the biological community to be related to hearing, but experiments have confirmed that its peculiar foot is used for breathing.

Within the membrane of the foot is a complex vascular system that transports and exchanges oxygenated and non-oxygenated blood. Crab crab, orange-red egg mass, white cream, nephrite-like crab meat, can be described as "a bucket of red jade, double chela out of the crispy fragrance." No wonder Tang Lu Chun said:

The taste of the four directions, when Xu Han Huang Bo (i.e., crab) first. "Because the crab is so delicious, the literati and ink writers did not hesitate to praise the flavor of the crab, such as the ancient poem

The taste is especially recommended wine, and the fragrance is the most suitable orange. The shell is thin and rouge-stained, and the ointment is amber. "The image of crab meat is beautiful.

The Yellow Valley's "one belly of metallographic jade, two chelates of the bright moon and autumn river", said that crab flavor can help people Yaxing.

No, there is a unique crab called the Short-fingered Monk Crab, which often walks forward. This crab can often be seen on the seashore of Xiamen.

Because the crab's forward movement function is degraded, the crab can only walk sideways.

Crab lateral walking is due to the fact that the forward movement function of the crab's walking joint is almost degraded, so it is transverse. Action crabs have compass-like magnetic particles on their bodies that guide the direction of the crab's movement, so the crab walks sideways to the inefficient brain to think about the direction.

Habits:A small group of crabs breed entirely in freshwater, and they mostly inhabit the rocks of mountain streams. There are also a few crabs, such as ground crabs, that can adapt to life on land, burrowing in damp mud holes, and migrating to the sea during the breeding season.

The vast majority of crabs are omnivorous. Some crabs are carnivorous, such as pike crabs.

It can prey on fish, shrimp and molluscs.

Wait. A few crabs, such as the crab, scrape or filter feed on algae.

and organic detritus.

The above content refers to Encyclopedia - Crab.

Crabs have chests that are wider from side to side than front to back, and their legs are on both sides, and their forefoot joints can only bend downward, unable to turn outward, and unable to bend backwards with their knees, so that crabs can only walk sideways.

Because its chest is wider than the front and back, the steps are on both sides, the forefoot spike joints can only bend downward, can not turn outward, the knee can not bend backwards, the inner ear has a directional magnet, because the earth's geomagnetic north and south poles have been reversed many times, so that the crab's small magnet loses its orientation, so the crab can only walk sideways.

Crabs: Crabs belong to the class molluscs, decapods, and are crustaceans, whose bodies are protected by hard shells and breathe by gills. Taxonomicly, it is the same animal as shrimp, lobster, and hermit crab.

The vast majority of species of crabs live in the sea or near the sea, but some inhabit freshwater or land. Common crabs include pike crab, open-sea pike resistant pure crab, blue crab and Chinese mitten crab (river crab, hairy crab, clear water crab) and so on.

Because its chest is wider than the front and back, the steps are on both sides, the forefoot joints can only be bent downward, can not be turned outward, the knees can not be bent backwards, and the inner ear has a directional magnet, because the earth's geomagnetic north and south poles have been reversed many times, so that the small magnet of the crab has lost its directional effect, so the crab can only walk sideways.

Crabs: Crabs belong to the class Mollusk, the order Ten Spring Feet, are crustaceans, the body is protected by a hard shell, and it breathes by gills. Taxonomicly, it is the same animal as shrimp, lobster, and hermit crab.

The vast majority of species of crabs live in the sea or near the sea, but some live in freshwater or land. Common crabs include pike crab, open sea pike crab, blue crab and Chinese mitten crab (river crab, hairy crab, clear water crab) and so on.