What is the evolutionary process of crabs ?

Crustaceans in arthropods. The whole body has a carapace, a well-developed cephalothorax, and a vestigial abdomen, commonly known as the "umbilicus", the pointed umbilicus of the male, and the mass umbilicus of the female. There are five pairs of feet, and the first pair of feet are in the shape of pincers, called chela, which is used to prey and defend against enemies.

Crawl sideways. There are many types, such as river crabs and pike crabs. The meat is delicious.

The body of the crab is divided into cephalothorax and abdomen. The back of the cephalothorax is covered with a cephalothorax, and the shape varies depending on the species. The frontal part has a pair of antennae, and the outer side is a stalked compound eye.

The mouthparts include 1 pair of large jaws, 2 pairs of small jaws, and 3 pairs of jaws. There are 5 pairs of breasts and feet on both sides of the cephalothorax. The abdomen is vestigial, flattened, and zigzags on the ventral surface of the cephalothorax.

The abdomen of males is narrow and long, mostly triangular, and only the first two pairs of appendages are deformed into handicapsThe female has a broad abdomen with a pair of double-branched appendages in the 2nd and 5th segments, densely covered with bristles, which are used to hold eggs.

The crab seeds hatch from eggs into small crab seedlings, and after several peels, they slowly turn into large crabs. Crabs will save themselves by suddenly amputating their limbs when they encounter "enemies".

The horseshoe crab is a type of crab, and the earliest types of crabs can be found from geological history to determine its possible time of origin and evolutionary history. No matter how incomplete the fossil data, phenotypic evidence of the crab's ancestors always leaves a trail. But the genetic evidence of the crab's ancestors has long been irretrievably lost.

Chinese eating crabs first began in the Song Dynasty, the first emperor of the Song Dynasty to eat crabs, Song Renzong. In addition, Ouyang Xiu, a writer of the Song Dynasty, also liked to eat crabs very much. According to the Shenzhen Post-80s Quartet Forum, Chinese take crabs as "the world's delicacy", such as "spicy crab", "crab stuffed orange", "steamed river crab", "crab roe soup bun", "crab roe lion head" ......They are all delicacies that are deeply loved by Chinese.

Chinese eating crabs first began in the Song Dynasty, the first emperor of the Song Dynasty to eat crabs, Song Renzong. Let's introduce how ancient people ate crabs

According to reports, Song Renzong has loved to eat crabs since he was a child. He was not only the first emperor of the Song Dynasty to eat crabs, but also led the people of the Song Dynasty to start eating crabs, and the custom of eating crabs has been passed down in China. According to historical records, Song Renzong loved to eat crabs when he was a child, and he was so hungry that he panicked when he didn't eat a meal, and he couldn't stop the car when he ate it.

Because he ate too much crab and was too uncontrolled, he finally had a problem with eating: dizziness, numbness in his limbs, coughing and spitting, and often constipation.

Although crabs are a good thing, they are cold and should not be eaten more, and if you eat too many crabs, you will get "wind and phlegm". What is Wind Phlegm? It's Song Renzong's symptoms.

At that time, Song Renzong was still young and had not yet been in power, and it was his titular mother, Empress Dowager Liu, who was really in power. Empress Dowager Liu saw that the little emperor had eaten crabs and damaged his body, and immediately issued an edict: shrimp, crabs and seafood must not be banned!

According to Sima Guang's "Chronicles of the Flowing Water", not only crabs, but also shrimp were not allowed to be sent to the palace at that time!

Song Renzong, who likes to eat crabs, wanted the eunuch palace maid to secretly go outside to buy crabs to eat, but everyone was afraid of Empress Dowager Liu's severe punishment and did not dare to agree. At this time, another queen mother couldn't stand it, she was the good sister of the Empress Dowager Liu, the Empress Dowager Yang who personally raised Song Renzong, and the Empress Dowager Yang said: Why did the Empress Dowager abuse my son like this?

You don't let him eat crabs, I'll let him eat them! So she often quietly got some crabs for Song Renzong to eat.

Later, when Song Renzong grew up, he was very grateful to Empress Dowager Yang, but he was resentful of Empress Dowager Liu. Why did he resent Empress Dowager Liu? Half of it was because Empress Dowager Liu had been listening to politics for too long; The other half is because Empress Dowager Liu won't let him eat crabs.

Chinese eating crabs first began in the Song Dynasty, and it was precisely because of this emperor's drive.

The growth cycle of crabs varies depending on the species and environmental conditions. Generally speaking, the growth cycle of hairy crabs is 1-2 years, and in the right environment, they can live up to 20-30 years.

Under the condition of moderate temperature and sufficient food, the growth period of hairy crabs is about 10 months to one year, that is, each layer of skin, a little older, and a total of dozens of times in a lifetime, until they become adult hairy crabs. And if the environmental conditions are poor, such as the temperature is too high or too low, and the food is insufficient, the growth cycle of hairy crabs may be longer.

In the natural environment, the lifespan of river crabs is generally only 1-2 years, while in the environment of artificial breeding, due to proper feed and daily management, the life span of river crabs can be longer.

In addition, the growth cycle of crabs is also affected by the sex of the object. In general, male hairy crabs have a shorter growth period than female hairy crabs, because male hairy crabs do not need to reproduce and take care of their offspring after maturity.

In conclusion, the growth cycle of crabs varies depending on the species and environmental conditions, but in general, crabs have a longer growth period and need to go through multiple molts and growth processes before they mature.

The growth cycle of crabs is 1 year. Crabs live in the sea or near the sea, and some inhabit freshwater or land. Relying on the female crab to give birth to the small Li sedan crab, each time the female crab will lay a lot 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.

The queen crab refers to the female blue crab with fat and tender meat. The blue crab has the reputation of "sea ginseng", the blue crab has a round appearance, the whole body is blue, the appearance is quite high, the meat is fresh and sweet, even the big foodie Su Shi commented on it: "The half shell contains yellow and should be ordered to drink, and the two chelates are persuaded to add food."

Crab queen series products are rich in nutrition, especially vitamin A up to more than 5,000 IU, more than 16 times that of shrimp. From the Mid-Autumn Festival to the beginning of winter, its eggs, liver, feet and muscles are very plump and tender. Its meat is delicious and unique, extremely rich in nutrition, known as the delicacy of the banquet, the edible medicinal value is high, known as the reputation of ginseng in the sea, it is a high-grade tonic for mothers, the old and the young and the weak.

The famous blue crab. For example, Taishan blue crab, according to the growth process is subdivided into dying crab (blue, white, yellow, black four grades), paste crab, water crab, meat crab, heavy shell crab (about to fade, also weighed skin crab), butter crab (divided into two kinds of anointment oil, water and oil), etc., in addition to the appearance of the saw-edge blue crab, the body surface is extremely smooth and shiny, the cephalothorax and appendages are pale green, the chelicerae is large and the carapace is thin, the crab meat is white and delicate, and the meat yield is high.

In 2017, the former Ministry of Agriculture approved the registration and protection of national agricultural product geographical indications for Taishan blue crabs, and the protected areas include 8 towns in Taishan, including Duhu, Chixi, Guanghai, Haiyan, Chuandao, Wencun, Beiqiao, and Shenjing. The continuous improvement of tens of thousands of acres of breeding scale and crab farming technology has made the development of the local blue crab industry gradually move towards scale, specialization and standardization.

The crabs I raise are seedlings in the beginning of spring 2 March. If it's to feed icefish. You can grab and sell before the Mid-Autumn Festival.

The growth cycle of crabs is 1 year, and it takes more than half a year from the beginning of crab seedlings to maturity

The vast majority of species of crabs live in the sea or near the sea, but some inhabit freshwater or land. They rely on the mother crab to give birth to baby crabs, and each time the mother crab lays a large number of eggs, the number of which can reach more than millions. Crabs rely on the geomagnetic field to determine direction.

The genetic material of such organisms is complex and highly varied, often as many as more than 100 pairs. The vast majority of species of crabs live in the sea or near the sea, but some inhabit freshwater or land. They rely on the mother crab to give birth to baby crabs, and each time the mother crab lays a large number of eggs, the number of which can reach more than millions.

Crabs rely on the geomagnetic field to determine direction. The genetic material of such organisms is complex and highly varied, often as many as more than 100 pairs. The vast majority of species of crabs live in the sea or near the sea, but some inhabit freshwater or land.

They rely on the mother crab to give birth to baby crabs, and each time the mother crab lays a large number of eggs, the number of which can reach more than millions. Crabs rely on the geomagnetic field to determine direction. The genetic material of such organisms is complex and highly varied, often as many as more than 100 pairs.

The vast majority of species of crabs live in the sea or near the sea, but some inhabit freshwater or land. They rely on the mother crab to give birth to baby crabs, and each time the mother crab lays a large number of eggs, the number of which can reach more than millions. Crabs rely on the geomagnetic field to determine direction.

The genetic material of these organisms is complex and highly variable, with more than 100 pairs often occurring in the sea or offshore areas for most species, and some inhabiting freshwater or land. They rely on the mother crab to give birth to baby crabs, and each time the mother crab lays a large number of eggs, the number of which can reach more than millions.

On July 1, 2009, Crab Secret won the favor of the best online goods in the ** support plan with its excellent visual expression, and participated in three theme promotion activities, and its sales have been growing by leaps and bounds. On August 15, 2009, the single-day sales exceeded 6,000 yuan, and the ranking of the search category rose steadily, making Crab Secret have a certain traffic base, and the conversion rate once exceeded 8%. In November 2009, the company expanded from the original 4 people to 18 people, and the e-commerce professional team began to be established.

In December 2009, he joined the Tao brand Crab Secret is the first intimate clothing creative agency to enter the Tao brand! With the dual improvement of internal management and external resources, sales have skyrocketed.

Everything in the world has a reason for its origin, and hairy crabs are no exception. We all know that pigs, cows, horses, and sheep are developed after the mating of males and females to produce embryos. In fact, hairy crabs are the same thing, and they are also mated by male and female crabs.

Every year in the spring season, when the temperature is around 15 to 20 degrees Celsius, sexually mature hairy crabs enter the mating season. At this time, adult hairy crabs generally use another pheromone (chemical scent) to attract the opposite sex. The male crab releases pheromones and then uses his claws to fan the scent to the courting partner, sometimes moving towards the female at the same time.

After chemical bonding, the pair of hairy crabs will perform a premating hug, with the male wrapping his paws and thighs around the female. Copulation begins after this intimate hug, just like any other animal, and is a process of fertilizing an egg.

A few days after mating, the female produces eggs like fish roe, and when these eggs hatch and mature on the belly of the female crab, they will break away from the mother crab with the current and slowly develop into small crabs.

In fact, the growth process of hairy crabs is divided into eight stages: fertilized eggs, larvae, big-eyed larvae (crab seedlings), young crabs (bean crabs), juvenile crabs (buckle crabs), yellow crabs (June yellow), green crabs (adult crabs) and broodstock crabs. It takes two years for a lifetime to grow.