In the waters of Poyang Lake, China's largest freshwater body, scientists have identified a species of protozoan previously unknown to science. The new organism has been named the "Jiujiang stentor" (Stentor jiujiangensis), after the place of its discovery in Jiangxi Province. The discovery, published in August 2026 in the journal Zootaxa, marked the first case of a representative of the genus Stentor being described on the territory of the country.
Researchers from the Jiujiang field station of the Ministry of Agriculture and Shanghai Ocean University collected samples during routine monitoring. Under the microscope, a cell measuring 115–200 micrometres stood out for the stable yellow-green colour of its cortical granules and a single large nucleus. Genetic barcoding confirmed significant differences from the more than twenty already known species of the genus.
Stentors have long served as living sensors of water quality. These ciliates react sensitively to the slightest changes in chemical composition, temperature and oxygen content. Their presence or disappearance makes it possible to judge the state of the entire ecosystem long before the problems become noticeable to larger organisms.
Poyang Lake is a key hub of the Yangtze river network. Here bird migration routes intersect, fish spawn, and microscopic life provides the foundation of food chains. The appearance of a new species indicates that measures to restore the basin are bearing fruit: the water is becoming cleaner, and biological diversity richer even at the level of single-celled organisms.
The discovery adds to the world collection of freshwater protozoans and at the same time reminds us that care for the environment does not begin only with large mammals or forests. Preserving the purity of rivers and lakes directly affects inconspicuous but vitally important inhabitants, whose well-being reflects the health of the entire planet.
Every such find strengthens the understanding of how closely all levels of life in freshwater systems are intertwined.
