Hairy crabs, also known as river crabs and hairy crabs, scientific name Chinese river crabs (Eriocheir sinensis) are crustaceans in the family Eriocheir sinensis. Their chelicera-footed (pincers) are thick and powerful, with serrations inside. Male crabs have thick villi on the inside and outside of their chelicera. Hairy crab is a unique species of Chinese mainland, divided into four major strains: Yangtze River system, Yellow River system, Haihe River system and Liao River system, of which the Yangtze River system is the most famous.
First, the origin of the name of hairy crab
According to legend, Xia Yu treated the water and appointed the PLO supervisor, at that time, a kind of sandwiching insect often appeared in the water, injuring countless people, and then the PLO burned it to death with boiling water and ate its flesh, but found that this worm was delicious, so he advertised everyone; At this point, the human insect is no longer feared, but has become food. In order to commemorate the bravery and discovery of the PLO, later generations added worms under the word and called it crab. This crab is the later hairy crab. So why is it called hairy crab? There are several different versions of this. First of all, some people think that the sound of the word "gate" and the word "boil" are similar, which is a change in the square sound. Secondly, some people think that the dictionary has the word "煠", that is, it is interpreted in steamed water. There is also a saying that when Wu Neshi made a crab banquet at his house, Mr. Zhang Weiyi revealed for the first time, he said: "The gate is good, and all crab hunters, they must set up a gate between the harbors, made of bamboo." Come to the gate at night, set a light, crab sees the fire, that is, climb on the bamboo gate, that is, catch it one by one on the gate, which is very convenient, which is the origin of the name crab. ”
Second, the migration and breeding of hairy crabs
Hairy crabs have the habit of migrating, they are born in the shallow sea of the estuary, and then go up the river, grow and fatten in the freshwater rivers and lakes, and after the completion of the reproductive molting every autumn, the mature individuals leave their growth and fattening residences, go down the river to the shallow sea area of the estuary, and mate and lay eggs here, after which the female crab overwinters with eggs, the fertilized eggs develop on the abdominal navel of the female crab, and the fleas-like larvae after rupture leave the female crab, and then develop into big-eye larvae after 5 molts. At the same time, it can also adjust the osmotic pressure to adapt to the freshwater environment), the big-eyed larvae go up the river, as far as Chongqing, during which they experience non-stop molting and growth, and then settle and fatten when they encounter a suitable environment, and after about a year and a half, grow into sexually mature individuals in the fall of the following year, and then go down the river to the shallow sea area of the estuary to mate and spawn, completing the mission of racial continuation. The life cycle of hairy crabs is generally 23-25 months, and male and female crabs generally die after completing their breeding mission.
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Third, the male and female of hairy crabs
The belly of the crab is vested and folded below the head and thorax, commonly known as the umbilicus. In the crab stage, the crab navel is pointed and long, and when it grows up, the male belly narrows in an isosceles triangle, called the pointed umbilicus, while the female abdomen becomes wider, approximately semi-circle, commonly known as the group umbilicus. In addition, mature male crabs have a circle of ground hair on their feet, while female crabs do not.
The picture on the left shows early maturing crabs, and the picture on the right shows crab seedlings; The upper part is the female crab, and the lower is the male crab
Fourth, hairy crab land liver, pancreas and gonads
The liver and pancreas, commonly known as crab roe, is an important digestive gland of crab, the left and right lobes are composed of many branch-like blind tubes, and a pair of liver tubes lead to the midgut, transporting digestive juices to help food digestion; A healthy liver and pancreas are orange. The liver and pancreas are also the nutrient storage organs of hairy crabs, and after the hairy crabs complete the reproductive molt, the nutrients stored in the liver and pancreas are gradually consumed, and the liver and pancreas become smaller, replaced by the development and growth of the river crab's gonads.
(Some of the content and pictures in this article are from online articles)