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Autumn wind, crab feet itch; When chrysanthemums bloom, they smell crabs. It's time to enjoy flowers and crabs again. Hairy crabs have a long reputation. Hairy crab is a kind of river crab, and its scientific name is Eriocheir sinensis.

The origin of the name of hairy crabs is said to be named after the method of "grasping crabs with your fingers". Once upon a time, crab catchers built a series of small doors in the lake with bamboo pieces or reeds, also called "crab sticks". At night, people hang lights on the gate, crabs scramble to climb the bamboo gate, and crab catchers can catch them with their hands as long as they keep the lights on. The crabs caught on the hair clasp are all called "Zhaxie" in Wu language in Suzhou area, and those who can climb the hair clasp are often larger, so the word "big" is added before "Zhaxie".

Eriocheir sinensis is widely distributed in fresh water areas from Liaohe River in the north to Pearl River in the south of China, and the Yangtze River system has the largest output. They breed near the Yangtze estuary, grow into young crabs and migrate against the Yangtze River, growing in the tributaries of lakes and rivers in the lower reaches of the Yangtze River. Yangcheng Lake hairy crabs are the most famous cultured species.

There are actually many kinds of crabs. In addition to river crabs, more species belong to sea crabs. According to the ecological classification, it can be divided into walking crab, swimming crab, burrowing crab, hidden crab and raw crab.

Walking crabs move slowly, so it is difficult to prey on fast-moving prey. But their big claws are suitable for dealing with thick-shelled prey such as shellfish, and they can also dig worms and swallow plants. Portunus can swim, among which Portunus is the best. Its swimming power comes from the last pair of feet, and at least two flat ones are used as paddles. There are two kinds of cave crabs: one is to dig a hole temporarily and bury yourself in it as a temporary shelter; Another kind of cave crab can build a real cave and hide for days or weeks. Also called cave crab. The body color of the hidden crab can change with the change of environment.

The crab has five pairs of chest feet on both sides of its head and chest. Except for the first pair of stinging feet, the other four pairs are walking feet. The crab's spiny feet are like two big pliers, which are not only its prey tools, but also its weapon against the enemy.

No matter what kind of crab walks, it is overbearing and arrogant, so it is called "wandering intermediary" and is unique among animal groups. Because the joints of our feet can only move left and right, we have to push sideways with one foot and run wild with the other foot on the ground. In addition, because several pairs of feet on the same side are long at the front and short at the back, they can only turn around when encountering obstacles.

Crabs seem arrogant, but they also have many natural enemies, such as wading birds such as red-crowned cranes. The red-crowned crane has good eyesight. It can easily find crabs moving 10 meters away, then quickly rush up, catch them before they enter the hole, and throw them on the hard ground, so that they lose the barrier to escape. Red-crowned cranes are like cats playing with mice. It uses its powerful beak to break off the feet of crabs one by one and swallow them one by one.

In order to avoid the capture of natural enemies, crabs like to hide under stones or dig caves in muddy beaches. Caves vary in depth, but each cave often has two caves. Crabs hibernate deep in the cave bottom in winter, and then climb out of the cave when it is warm in spring, ready to breed. The peak of crab activity every day is after dark. At this time, almost all individuals gushed out of the cave, all over the roads and rivers, which were dense and spectacular from a distance.