The Yangtze River, known as Chang Jiang in China, is Asia’s longest river and the third longest globally, stretching approximately 3,977 miles (6,400 kilometers) from the Tibetan Plateau to the East China Sea. This extensive waterway supports a vast array of life, contributing substantially to global biodiversity by providing crucial habitats across diverse ecosystems.
Aquatic Life Diversity
The Yangtze River system harbors a diverse range of aquatic life, making it one of the most biodiverse freshwater regions worldwide. Its waters are home to hundreds of fish species, including around 378 types. The basin also supports approximately 145 species of amphibians, 166 species of reptiles, and over 280 mammal species. Various invertebrate groups, such as mollusks and insect larvae, form foundational components of the river’s food webs.
Notable Mammals and Reptiles
The Yangtze River is home to several notable mammalian and reptilian species. Among these, the Yangtze finless porpoise (Neophocaena asiaeorientalis asiaeorientalis) is a unique freshwater cetacean, distinguished by a narrow ridge with wart-like tubercles instead of a dorsal fin. This critically endangered porpoise inhabits the main stem of the Yangtze River and its connected lakes, feeding on fish, mollusks, and crustaceans. It navigates and locates prey using echolocation.
Another significant resident is the Chinese alligator (Alligator sinensis), a smaller crocodilian species, typically 4 to 5 feet long. Its body is covered in protective bony plates, or scutes. These alligators prefer slow-moving freshwater habitats like swamps and ponds within the lower Yangtze basin, where they are largely nocturnal and dig burrows for shelter. Their diet consists of snails, crustaceans, insects, fish, and small mammals.
Historically, the Yangtze River was also home to the Baiji dolphin (Lipotes vexillifer), often called the “Goddess of the Yangtze.” This river dolphin is now considered possibly extinct, with no confirmed sightings in over two decades. Its decline was largely attributed to intense fishing pressure, bycatch in nets, habitat degradation, increased pollution, and heavy shipping traffic. The construction of dams further fragmented its habitat.
Specialized Fish and Amphibians
The Yangtze River supports a diverse array of specialized fish and amphibian species, many endemic to its waters. The Yangtze sturgeon (Acipenser dabryanus), a bottom-dwelling fish, historically found in the upper and middle reaches of the river and its tributaries. While once commercially important, this species is now considered extinct in the wild, relying on stocking programs for its continued presence. These sturgeons primarily feed on aquatic invertebrates like oligochaetes, crustaceans, and insect larvae, along with small fish.
Among the river’s amphibians, the Chinese giant salamander (Andrias davidianus) is the world’s largest amphibian, capable of reaching 1.8 meters. This fully aquatic creature, often referred to as a “living fossil,” thrives in cold, fast-moving mountain streams. It possesses poor eyesight but compensates with sensory nodes on its skin to detect vibrations from prey, which include crabs, shrimps, aquatic insects, fish, and frogs. The salamander breathes primarily through its porous, wrinkled skin.
The Yangtze River is noted for its high fish diversity, including 177 endemic species found nowhere else. Beyond the sturgeon, other fish species like the yellow head catfish and various carp species are abundant and form important links in the river’s food web. These species showcase unique evolutionary adaptations within this extensive river system.
Avian Residents and Invertebrates
The Yangtze River basin and its wetlands serve as a haven for many avian species, particularly migratory birds. The central Yangtze River and its lakes are significant wintering and stopover sites, hosting an estimated 95 percent of the world’s Siberian crane population. Other notable avian residents include Oriental Storks, various geese (like the White-fronted and Swan Goose), and different duck species (such as the Common Teal and Spot-billed Duck), alongside gulls, egrets, and herons.
These birds rely on the river’s rich aquatic resources, utilizing wetlands for feeding and breeding. Recent conservation efforts focused on habitat restoration have shown encouraging signs, with overall bird diversity increasing in some areas of the basin. However, wetland bird species in downstream regions continue to face challenges, highlighting the ongoing need for protective measures.
Beneath the water’s surface, diverse invertebrate communities form the base of the Yangtze’s aquatic food web. Macroinvertebrates, including freshwater crabs (like the Chinese mitten crab), mollusks (such as bivalves and gastropods), and insect larvae (like chironomid midges and oligochaete worms), are widespread. These organisms are integral to the river’s ecosystem, contributing to secondary productivity and energy transfer through the food chain. Their presence and diversity are closely linked to the overall health and water quality of the river system.