Aerial photo taken on July 21, 2020 shows rice fields at Hujia Town of Panjin City, northeast China's Liaoning Province. Panjin City has not only China's high-quality rice production base, but north China's larger river crab artificial incubation and breeding base. The city has developed a rice-crab commensal eco-agriculture mode that river crabs are bred in growing rice. This mode has created a new method for farmers planting rice to increase incomes. (Xinhua/Yao Jianfeng)

A staff member of a crab production company shows a river crablets bred in rice fields in Panjin City, northeast China's Liaoning Province, July 16, 2020. Panjin City has not only China's high-quality rice production base, but north China's larger river crab artificial incubation and breeding base. The city has developed a rice-crab commensal eco-agriculture mode that river crabs are bred in growing rice. This mode has created a new method for farmers planting rice to increase incomes. (Xinhua/Yao Jianfeng)

Aerial photo taken on July 21, 2020 shows farmer Zhang Haitao checking the growth of rice seedlings and river crabs bred in rice fields at Hujia Town of Panjin City, northeast China's Liaoning Province. Panjin City has not only China's high-quality rice production base, but north China's larger river crab artificial incubation and breeding base. The city has developed a rice-crab commensal eco-agriculture mode that river crabs are bred in growing rice. This mode has created a new method for farmers planting rice to increase incomes. (Xinhua/Yao Jianfeng)

A staff member of a crab production company works at a rice-crab commensal field in Panjin City, northeast China's Liaoning Province, July 16, 2020. Panjin City has not only China's high-quality rice production base, but north China's larger river crab artificial incubation and breeding base. The city has developed a rice-crab commensal eco-agriculture mode that river crabs are bred in growing rice. This mode has created a new method for farmers planting rice to increase incomes. (Xinhua/Yao Jianfeng)

Photo taken on July 16, 2020 shows river crabs bred in rice fields in Panjin City, northeast China's Liaoning Province. Panjin City has not only China's high-quality rice production base, but north China's larger river crab artificial incubation and breeding base. The city has developed a rice-crab commensal eco-agriculture mode that river crabs are bred in growing rice. This mode has created a new method for farmers planting rice to increase incomes. (Xinhua/Yao Jianfeng)