The finless porpoise, nicknamed "smiling sprites" for their upturned mouths, is a key indicator species for the ecological health of the Yangtze. The urban stretch of the river through Nanjing is one of the few areas in China where wild populations maintain a stable habitat.
At the exhibition center, a 3.4-meter Chinese sturgeon specimen drew the group in for a closer look. The students peppered staff with questions about river conservation and biodiversity.
