Xiaoqing 2. 1 to 4. 1, Zhongqing 4.2 to 6.2, Daqing 6.2 or above. According to relevant public information, Xiaoqing, Zhongqing and Daqing all refer to the specifications of crayfish, usually expressed by "money". Xiaoqing 2. 1 to 4. 1, Zhongqing 4.2 to 6.2, Daqing 6.2 or above. Crayfish is high in protein, soft in meat and easy to digest, and it is food for people who are weak and need to be nursed back to health after illness.