Chinese paddlefish

The Chinese paddlefish (Psephurus gladius; simplified Chinese: 白鲟; traditional Chinese: 白鱘; pinyin: báixún: literal translation: "white sturgeon"), also known as the Chinese swordfish, is an extinct species of fish that was formerly native to the Yangtze and Yellow River basins in China. With records of specimens over 3.6 metres (12 ft) and possibly 7 m (23 ft) in length, it was one of the largest species of primarily freshwater fish. It was the only species in the genus Psephurus and one of two recent species of paddlefish (Polyodontidae), the other being the still-living American paddlefish (Polyodon spathula). The species was not a strictly freshwater fish, with individuals having migrated down the Yangtze into the sea as juveniles, where they spent time in coastal waters, before returning into the river by adulthood, and migrating upriver to spawn. Unlike the American paddlefish, which is a filter feeder on plankton, the Chinese paddlefish was a piscivorous predator that primarily consumed small to medium-sized fish.

Since the 1990s, the species was officially listed by the International Union for Conservation of Nature (IUCN) as critically endangered, and was last seen alive in 2003. A 2019 paper including scientists from the Yangtze River Fisheries Research Institute found the species to be extinct based on its absence from extensive capture surveys, with the extinction suggested to have occurred by 2005, and no later than 2010, although it had become functionally extinct by 1993. It was unanimously agreed to be extinct by the Species Survival Commission Sturgeon Specialist Group of the IUCN on 15 September 2019, with its conservation status being formally updated by the IUCN Red List in July 2022.

The main cause of its extinction was the construction of the Gezhouba Dam in 1981, fragmenting the population and blocking the migration of the fish to its upriver spawning grounds required to sustain its population. Overfishing also played a significant role in its decline. Fishing of the Chinese paddlefish dates back centuries, with annual harvests reaching 25 tons by the 1970s.