A Tectonic Cradle for Evolution
Fuxian Lake is a massive body of water formed by tectonic faulting between 2 and 5 million years ago. Located on the Yunnan Plateau at an elevation of 1,721 meters, it is China's deepest freshwater lake, plunging to a maximum depth of 155 meters. Its total water volume is immense, holding about 18.9 billion cubic meters. This deep and ancient environment was a site for evolution, giving rise to a unique "species flock"—a group of closely related species that evolved from a common ancestor within the lake itself.
Historically, the lake contained a diversity of aquatic life, including 24 native fish species and subspecies, 11 of which were found nowhere else on Earth. These endemic species, primarily from the cyprinid (minnow and carp) and stone loach families, adapted to fill various ecological niches within the deep, clear waters. Among the most famous was the Kanglang fish (Anabarilius grahami), a small minnow prized for its delicate flavor. Other unique inhabitants included the Fuxian carp (Cyprinus fuxianensis) and the Fuxian golden-line fish (Sinocyclocheilus tingi).
An Ecosystem Under Threat
The unique fish assemblage of Fuxian Lake has faced a catastrophic decline in recent decades. The primary cause has been the introduction of non-native species. In the early 1980s, Taihu icefish (Salangichthys taihuensis), also known as noodlefish, were introduced into the lake. This fast-breeding, voracious predator outcompeted native fish and consumed their eggs and larvae. The impact was swift and devastating. The annual catch of the endemic Kanglang fish plummeted from over 300 tons in the 1980s to less than one ton by 2002.
By 2005, the lake's fish community had dramatically shifted. Surveys found 19 non-native fish species, while only four of the original endemic species could be located. Today, several endemic species, such as the Fuxian carp (Cyprinus fuxianensis) and Poropuntius chonglingchungi, are considered possibly extinct, having last been seen in the 1990s. The once-abundant Kanglang fish (Anabarilius grahami) was pushed to the brink of extinction and is now classified as Vulnerable by the IUCN. Water pollution, habitat degradation, and overfishing have compounded the damage caused by invasive species. Conservation efforts, including fishing bans and artificial breeding programs to reintroduce native species like the Kanglang fish, are underway to save the remnants of this unique evolutionary heritage.