Fishermen catch crayfish at Longquan Lake in Xuyi County, east China's Jiangsu Province, May 15, 2014. Fishermen of Xuyi County started to harvest crayfish on Thursday. Crayfish is an important industry in Xuyi, yielding an output value exceeding 10 billion yuan (1.6 billion U.S. dollars). (Xinhua/Zhou Haijun)

Fishermen catch crayfish at Longquan Lake in Xuyi County, east China's Jiangsu Province, May 15, 2014. Fishermen of Xuyi County started to harvest crayfish on Thursday. Crayfish is an important industry in Xuyi, yielding an output value exceeding 10 billion yuan (1.6 billion U.S. dollars). (Xinhua/Zhou Haijun)

Fishermen catch crayfish at Longquan Lake in Xuyi County, east China's Jiangsu Province, May 15, 2014. Fishermen of Xuyi County started to harvest crayfish on Thursday. Crayfish is an important industry in Xuyi, yielding an output value exceeding 10 billion yuan (1.6 billion U.S. dollars). (Xinhua/Zhou Haijun)

Fishermen catch crayfish at Longquan Lake in Xuyi County, east China's Jiangsu Province, May 15, 2014. Fishermen of Xuyi County started to harvest crayfish on Thursday. Crayfish is an important industry in Xuyi, yielding an output value exceeding 10 billion yuan (1.6 billion U.S. dollars). (Xinhua/Zhou Haijun)

Photo taken on May 15, 2014 shows a crayfish at Longquan Lake in Xuyi County, east China's Jiangsu Province. Fishermen of Xuyi County started to harvest crayfish on Thursday. Crayfish is an important industry in Xuyi, yielding an output value exceeding 10 billion yuan (1.6 billion U.S. dollars). (Xinhua/Zhou Haijun)

Fishermen catch crayfish at Longquan Lake in Xuyi County, east China's Jiangsu Province, May 15, 2014. Fishermen of Xuyi County started to harvest crayfish on Thursday. Crayfish is an important industry in Xuyi, yielding an output value exceeding 10 billion yuan (1.6 billion U.S. dollars). (Xinhua/Zhou Haijun)