The pro-shellfish selection and stocking of green barley are abundant in the north coast of China. The breeding season is in the northern part of the country from late July to early September. During the breeding season, natural or artificially cultivated 2nd-instar shellfish are harvested. Individuals with selective gland maturation and integrity without injury are washed clean and stored indoors for a period of time, allowing them to excrete feces and sediment and promote ripening, as the pro-shellfish for artificial hatching.