<P> Many Yangtze fish species have declined drastically and 65 were recognized as threatened in the 2009 Chinese red list . Among these are two that are considered entirely extinct (Anabarilius liui liui and Atrilinea macrolepis), two that are extinct in the wild (Anabarilius polylepis and Schizothorax parvus) and five that are critically endangered (Chinese paddlefish, Euchiloglanis kishinouyei, Megalobrama elongata, Schizothorax longibarbus and Leiocassis longibarbus). Additionally, both the Yangtze sturgeon and Chinese sturgeon are considered critically endangered by the IUCN . The survival of these two sturgeon may rely on the continued release of captive bred specimens . The Chinese sturgeon and Chinese paddlefish are the largest fish in the river and among the largest freshwater fish in the world, reaching lengths of 5 m (16 ft) and 7 m (23 ft) respectively . Although listed as critically endangered rather than extinct by both the Chinese red list and IUCN, the continued survival of the Chinese paddlefish is questionable . Surveys conducted between 2006 and 2008 by ichthyologists failed to catch any, but two probable specimens were recorded with hydroacoustic signals . The last definite record was a 3.6 m - long (12 ft) specimen caught during illegal fishing in 2007; despite attempts to keep it alive, it died shortly afterwards . </P> <P> The largest threats to the Yangtze native fish are overfishing and habitat loss (such as building of dams and land reclamation), but pollution, destructive fishing practices (such as fishing with dynamite or poison) and introduced species also cause problems . About ​ ⁄ of the total freshwater fisheries in China are in the Yangtze Basin, but a drastic decline in size of several important species has been recorded, as highlighted by data from lakes in the river basin . Some experts recommend a 10 - year fishing moratorium to allow the remaining populations to recover . Dams present another serious problem, as several species in the river perform breeding migrations and most of these are non-jumpers, meaning that normal fish ladders designed for salmon are ineffective . For example, the Gezhouba Dam blocked the migration of the paddlerfish and two sturgeon, while also effectively splitting the Chinese high fin banded shark population into two and causing the extirpation of the Yangtze population of the Japanese eel . In an attempt of minimizing the effect of the dams, the Three Gorges Dam has released water to mimic the (pre-dam) natural flooding and trigger the breeding of carp species downstream . In addition to dams already built in the Yangtze basin, several large dams are planned and these may present further problems for the native fauna . </P> <P> While many fish species native to the Yangtze are seriously threatened, others have become important in fish farming and introduced widely outside their native range . A total of 26 native fish species of the Yangtze basin are farmed . Among the most important are four Asian carp: grass carp, black carp, silver carp and bighead carp . Other species that support important fisheries include northern snakehead, Chinese perch, Takifugu pufferfish (mainly in the lowermost sections) and predatory carp . </P> <P> Due to commercial use of the river, tourism, and pollution, the Yangtze is home to several seriously threatened species of large animals (in addition to fish): the narrow - ridged finless porpoise, baiji (Yangtze River dolphin), Chinese alligator, Yangtze giant softshell turtle and Chinese giant salamander . This is the only other place besides the United States that is native to an alligator and paddlefish species . In 2010, the Yangtze population of finless porpoise was 1000 individuals . In December 2006, the Yangtze River dolphin was declared functionally extinct after an extensive search of the river revealed no signs of the dolphin's inhabitance . In 2007, a large, white animal was sighted and photographed in the lower Yangtze and was tentatively presumed to be a baiji . However, as there have been no confirmed sightings since 2004, the baiji is presumed to be functionally extinct at this time . "Baijis were the last surviving species of a large lineage dating back seventy million years and one of only six species of freshwater dolphins". It has been argued that the extinction of the Yangtze River dolphin was a result of the completion of the Three Gorges Dam, a project that has affected many species of animals and plant life found only in the gorges area . </P>

Province of east china crossed by the yangtze river capital hefei