A tiny zigzag mussel from an Anhui river turns out to be an entirely new kind of animal

Sometimes a whole new branch of life is hiding in plain sight, in a river people walk past every day. In the Xinanjiang River in Xiuning County, Anhui Province, in eastern China, a shell collector named Xie Tianxiang picked up a tiny freshwater mussel — barely 3.4 centimetres (about 1.3 inches) long, its shell covered in an elegant zigzag pattern with dark green rays. When researchers studied its shell shape and its DNA, they found it matched nothing known to science: not just a new species, but a new genus — the wider grouping a species sits in, one step above species on the family tree. They named the genus Huizhou, after the old name for the region, and the species Huizhou xietianxiangi, honouring Xie. Until now, its small branch of the mussel family, a group named only last year, had exactly one known member; this is the second. The Yangtze River Basin already holds more than 70 kinds of freshwater mussel, and the team, writing in the journal Zoosystematics and Evolution, says many small, easily overlooked ones are probably still waiting to be found. Because this mussel is so far known from just this one stretch of river, they are urging careful surveys now, so it can be studied and protected before its home is damaged.

SDG 15 · Life on land