Volunteer Xie Shoujun (1st L) helps staff members to check a finless porpoise named as Tiantian at a national nature reserve in Shishou, central China's Hubei Province, Oct. 24, 2016. There are only around 1,000 finless porpoises, a dolphin-like freshwater mammal with iconic "grins" on the face, in the Yangtze River and two lakes that are linked to the busy waterway. (Photo/Xinhua)
