What is the external form of a river crab?

River crab, also known as lake crab, eight-legged crab, hairy crab, hairy crab, crab, Chinese mitten crab, belongs to the reptile suborder square crab crustaceans, for the crustaceans that grow in fresh water, it has hundreds of thousands of species in the world, and there are 500 species in China. This crab is native to China, because of its chelicerae dense villus, so its scientific name in animal taxonomy is Chinese mitten crab. The whole body of the river crab is dark green except for the feet and abdomen, and the abdomen is grayish-white.

Its head joins the thorax to become the cephalothorax, the main part of the crab's body. Its back is covered with a round and hard dorsal armor, which is undulating but symmetrical from side to side. In the middle of the anterior edge of the dorsal carapace is the frontal region, with 4 tooth processes, called frontal teeth, and 4 sharp teeth on the left and right sides, called lateral teeth.

The posterior side of the dorsal carapace is oblique medially, and the posterior margin is relatively straight at the junction with the abdomen. On either side of the forehead, there is a pair of compound eyes that protrude forward, and the peduncle has a large range of motion, sometimes straight, sometimes lying horizontally in the eye socket. The inner side of the compound eye, transversely under the forehead, has two pairs of antennae, the first pair is in front of the upper edge of the mouth frame, the tip is short, and the base is large.

Inside there is 1 sensory organ called the balancer; The second pair of antennae is located on both sides of the first pair of antennae and is called the outer antennae.

The outer form of the river crab is dark green on the back, grayish white on the ventral surface, and the head and thorax have been healed together, which is collectively called the cephalothorax, which is the main part of the body. The back is covered with a layer of hard dorsal armor (called cephalothorax, commonly known as crab bucket), and the abdomen of the river crab (commonly known as crab navel) is divided into 7 segments, bent forward, and attached to the ventral surface of the cephalothorax. The shape of the abdomen, in the process of growth, the female crab gradually becomes round, commonly known as the umbilicus, and the male crab is still narrow and triangular, called the pointed umbilicus, which is one of the most significant signs to distinguish between male and female.

The thoracopod is the appendage of the thorax, consisting of a pair of chelicerae and four pairs of gaites, which are the organs of movement. Chelicerae are powerful, pincer-shaped, and densely hairy on the palms, especially in male crabs, which is also one of the signs to distinguish between male and female. The second to fifth pairs of thoracic feet have the same structure and are also called gaites.

Portunid.

Barracuda crab: "Flying crab" is a synonym for "three-wart pike crab". Sea crab, English name: portunustrituberculatus, pike crab family portunidae, pike subcrab portuninae.

Place names: Barracuda crab, Gun Crab, Sea Crab, Sea Worm, Water Crab, Door Crab, Small Menzi, Scorpion, Cover Fish, Three-Point Crab, Child Crab, Flying Crab, Smoke Cricket. English name:

swimmingcrab。Sea crabs are divided into two parts: cephalothorax and abdomen. The cephalothorax is covered with prismatic cephalothorax, blue-gray, with a pair of well-developed chelicerae at the anterior end and four pairs of footsteps at the posterior end.

It is distributed in the sea areas of north and south China. Generally from south to north, March and May and September and October are the peak production seasons, and the output of Liaodong Peninsula in Bohai Bay is more in April and May. Three-wart crab is one of China's important export bestsellers, exported to countries and regions:

Japan, Hong Kong, Macau. Export ports: Liaoning, Hebei, Tianjin, Shandong, Jiangsu, Zhejiang, Fujian.

Generally, the sea crabs eaten in the north of China are mainly pike crabs.

That's it.

Meat crab: is the male crab in the sea crab blue crab, the meat crab is beautiful with meat, the crab meat of the high-quality meat crab is plump, smooth and sweet, there is a feeling of fragrance, the umbilicus of the crab is a triangular meat crab, the river crab is also called "crab" and "hairy crab", it belongs to the freshwater crab, often burrows in the mud bank of the river, river and lake marsh, nocturnal activity, feeds on fish, shrimp, animal carcasses and grains, often migrates to the estuary of the sea every autumn to lay eggs, hatches in March and May of the second year, develops into a juvenile crab, and then traces the meat of the river to be fresh and tender, It is a favorite food of people.

Meat crab blue crab with a triangular ventral umbilicus in the middle is a meat crab. Meat crabs are beautiful with meat, and the crab meat of high-quality meat crabs is plump, smooth and sweet, and has a fragrant feeling.

Blue crabs are produced all year round, but during the period from the third day of the eighth lunar month to the twenty-third day of the eighth lunar month every year, the shells of blue crabs are as strong as shields, and the claws are round and strong"In August, cockles arrive at a chicken"said. The famous poet Su Dongpo also wrote in the poem "Crickles" that "half a shell contains yellow should order wine, and two chelates should be cut to persuade the snow to add food".

Chinese name meat crab.

The foreign name is mud crab

Another name. The main raw material of blue crab.

Crab, condiments and spices.

Key nutrients.

Proteins, fats.

Main edible efficacy.

It has the effect of strengthening the waist and kidney, eliminating accumulation and strengthening the spleen, nourishing the heart and soothing the nerves.

Suitable for. It can be consumed by the general population.

Spleen and stomach deficiency, cold stool, loose stools, abdominal pain, recluse, wind chill and cold that have not healed or chronic wind diseases, including intractable ** itching disease, menorrhagia, menstrual pain, pregnant women should not eat.

River crabs, also called "crabs" and "hairy crabs", have a square shape and a hard texture of the cephalothorax formed by the combination of head and thorax. There is a pair of eyes on the front of the body and two pairs of sharp crab teeth on the sides. The pair of appendages at the very front of the crab are called chelicerae, and the surface is covered with villi; After chelicerae there are 4 pairs of footsteps, flattened and long; The abdominal limb has degenerated.

The male and female of the river crab can be distinguished by its abdomen: the female has a round abdomen, and the male has a triangular abdomen.

The river crab is a large crustacean with a body divided into 21 segments, and the whole body is divided into two parts: cephalothorax and abdomen because the head and thoracic segments heal each other. The back of the adult crab is inky, and the cephalothorax is on average 7 cm long and wide.

River crabs often burrow in the mud banks of rivers, rivers and lakes and marshes, nocturnal activities, feed on fish, shrimp, animal carcasses and grains, often migrate to the estuary of the sea to lay eggs in autumn every year, hatch in March and May of the second year, develop into juvenile crabs, and then trace the meat of the river to be fresh and tender, it is a food that is deeply loved by people.

The scientific name of river crab is Chinese mitten crab, which is a precious freshwater product, delicious and nutritious, and has high economic value.

Scientific name in Chinese. Chinese mitten crab.

Another name. River crabs, crabs, hairy crabs.

kingdom Animalia. Phylum Arthropods.

Yamen. Subphylum Crustacea.

Classes of soft armor. Subclass.

True soft carapace.

Eye-catching. subhead.

Gastric suborder. Family Bow Crab Family.

It belongs to the genus Mitten Crab.

Species of Chinese mitten crab.

The shell of crab can be used to refine the industrial raw material chitin, which is used in water and wastewater purification, and is used as a food additive in medicine to thicken and stabilize the state of food and medicine. Chitin can also be used as a dye, fabric, adhesive. Chitin is also used for the size and strength of the processed paper.

Each 100 grams of crab edible part contains 182 mg of protein, 182 mg of fat, 182 mg of phosphorus, 126 mg of calcium, and rich in vitamin A and vitamin B1.

The components of the blue crab are rich in protein, among which the content of female gonads is as high, which is the highest protein content in fresh products. In addition, the protein amino acids of the blue crab are complete, and the essential amino acid score is.

The function of the crab shell: to protect the crab's shell.

1. Crabs are rich in protein, high cholesterol and high purines, gout patients should self-control when eating, and people with colds, hepatitis and cardiovascular diseases should not eat crabs. China has a tradition of eating river crabs around the Mid-Autumn Festival, because traditional Chinese medicine believes that crabs are cold, so ginger, perilla and other spices used for crabs are commonly used.

2. Crabs are rich in protein and trace elements, which have a good nourishing effect on the body. Crab contains more vitamin A, which is helpful for keratinization. Crabs also have anti-tuberculosis effects, and eating crabs is very beneficial to tuberculosis.

You can protect yourself when it's hard, and you can't even beat shrimp when it's soft.

Appearance characteristics: green and withered back, white belly, golden claws, yellow hair, strong body.

1. Green back: The back of the crab is a green crab shell and the shell is very thin, green and shiny, refreshing, smooth and shiny.

2. White belly: The navel belly carapace pasted with mud is crystal white and has no black spots, giving people a sense of beauty like water and jade.

3. Yellow hair: The fluff on the crab legs and the whiskers on the crab claws are golden yellow, the crab velvet is dense and soft, the hairs on the crab claws are refreshing and yellow, and the roots are straight.

4. Golden claws: Crab claws are golden, solid and powerful, placed on a glass plate, eight-legged erect, majestic, and crawling freely.

5. Strong: The crab is strong, thick and strong.

Do you know the difference between river crabs and crabs? Crab is a food that we all love to eat, and eating crabs will make people feel very happy, so do you know the difference between river crabs and crabs? Let's take a look at the difference between river crabs and crabs.

River crabs and crabs. Differences

1. The body shape and body structure are different, the river crab is a large crustacean, the body is divided into 21 segments, the back of the adult crab is inky, and the head and chest are 7cm long and wide on average. Crabs, on the other hand, are very small, but they have all the organs. After the hard shell of the crab is removed, the body of the crab is symmetrical and can be divided into frontal area, eye area, heart area, liver area, stomach area, intestinal area, and gill area.

3. The breeding method is different, the river crab floats in the shallow sea of the estuary for more than 35 days, and after 5 molts, it enters the larval stage of big-eyed. At this time, it also has a planktonic and benthic life, and can go up to lakes and marshes against the current. Bigeye larvae molt after 6 to 10 days to become juveniles and begin to live a benthic crawling life.

Crabs rely on female crabs to give birth to baby crabs, and each time the female crab lays a large number of eggs, the number of which can reach more than millions. After these eggs hatch in the belly of the mother crab, the larvae can break away from the mother and float around with the coastal currents. After several shells, they grow into big-eyed larvae, and the big-eyed larvae grow into juvenile crabs after several shells, and the appearance of juvenile crabs is almost the same as that of adult crabs, and then after several shells, they become crabs.

1. Although river crabs and sea crabs are both crabs, there are significant differences between the two, the most obvious being the difference in living environment. One lives in a freshwater river and the other in the ocean.

2. Then there is the difference in appearance. The size of the river crab is relatively small, and there are fine hairs on the crab claws and legs, and the species is single; On the other hand, sea crabs are relatively large, hairless, and have a variety of colors.

3. In terms of taste, river crab is better than sea crab, and the meat quality of river crab is relatively delicate and firm; The meat of sea crabs is looser, and the taste is not as good as that of river crabs.

4. From the point of view of purchasing, river crabs must be bought alive, and the dead ones are poisonous; And most of the sea crabs are frozen, because they die when they are caught.

5. In terms of nutrition, river crabs and sea crabs are comparable. At the same weight, the contents of vitamin A, vitamin B1, vitamin B2 and vitamin E were higher than those of sea crabs, while the contents of calcium, potassium and magnesium were lower than those of sea crabs. However, river crabs have much higher cholesterol levels than sea crabs.