A farmer harvests crayfish. [Photo/zjgonline.com.cn]

The markets in Zhangjiagang, a county-level city in Suzhou, East China's Jiangsu province, recently welcomed the arrival of crayfish to their sales counters.

Zhu Lixin, a farmer in Jiaotong village, Jinfeng town, said his farm currently produces about 25 kilograms of crayfish every day and that the yield will increase to more than 100 kg in early June.

Each kilogram of crayfish can sell for 17.5 yuan ($2.6).

At Zhu's farm, crayfish are raised in rice paddies when the fields are not in the fallow period. Crayfish feed on the insects in the rice fields and their droppings can fertilize the plants.

Each mu (666.7 square meters) of the fields can generate more than 8,000 yuan in net profits, said Zhu.