Chinese Sturgeon

The Chinese sturgeon (Acipenser sinensis) is a critically endangered anadromous species endemic to China, spending most of its adult life foraging in the Yellow Sea and East China Sea before undertaking an extraordinary migration of well over a thousand kilometers up the Yangtze River to spawn. A member of the ancient family Acipenseridae, it is one of the oldest surviving vertebrate lineages in Asia. Construction of the Three Gorges Dam and other river barriers has blocked access to historic spawning grounds, and natural reproduction in the wild is believed to have effectively ceased, making the species dependent on captive breeding and release programs for its continued survival.

The Chinese sturgeon shows classic sturgeon features on a large scale:

• Bluish-gray dorsal surface contrasting with a white underside
• Long, conical, pointed snout with four barbels set ahead of the mouth
• Five rows of prominent bony scutes running the length of the body
• Robust, torpedo-shaped body reaching 2-3 meters
• Heterocercal, asymmetrical tail fin Its large size, conical (rather than paddle-shaped) snout, and armored scute rows separate it from the unrelated and now-extinct Chinese paddlefish that once shared the Yangtze. Migratory adults are noticeably larger and darker than the juveniles seen in downstream nursery areas of the river.

As an anadromous species, the Chinese sturgeon spends the majority of its adult life in coastal marine waters of the Yellow Sea and East China Sea, feeding along the continental shelf. To reproduce, it migrates enormous distances upstream into the Yangtze River, historically reaching far into the upper river before dam construction curtailed access. It requires gravel or rocky river substrate for spawning and cool, well-oxygenated flowing water, conditions now largely disrupted by hydroelectric development along the Yangtze. Juveniles rear briefly in the estuary before moving out to sea to mature.

Adult Chinese sturgeon feed on benthic invertebrates and small fish while at sea, building energy reserves for their long spawning migration. Beginning in summer, sexually mature adults travel upstream against strong currents, arriving at spawning grounds in autumn to release eggs over rocky riverbed substrate. Juveniles subsequently drift back downstream toward the estuary and sea. The species is critically endangered, with wild spawning runs now extremely rare, and conservation authorities rely heavily on hatchery-reared juveniles released into the river to sustain the population.