Visitors watch the rare Tiebei fish species in the Crescent Spring scenic area in Dunhuang City, Northwest China's Gansu Province, May 1, 2016. The fish has been seen in the spring after disappearing for years, and its reemergence has attracted much attention. The local government has increased environmental protection for the spring, which has been a popular spot for tourists since the Han Dynasty (206 B.C.-A.D. 220). (Photo: China News Service/Wang Binyin)