Chinese sucker (Myxocyprinus asiaticus) is endemic to China or even Asia.The fish is naturally distributed in Yangtze river and Minjiang river basins.The species is also well known in China for the big body of the adult over one meter. Otherwise,the color of the fish is very fantastic with a wide horizontal red stripe along each lateral side of the body to the snout in adult fish. So it is also called as “kermes" fish in China.Wild population of the fish has been declining rapidly in the last several decades because of the impact of human interference.The fish has been listed as Category Ⅱ species under national key protection in China.
Chinese sucker was thought as a migratory fish in many certain literatures.It is said in the literatures that the fish laid eggs in Minjiang,Jialingjiang and main sections of the upper-reach of Yangtze basins.After hatching,larvae of the fish migrated to the middle and lower reaches of Yangtze river basin.Until growing up to near maturity,the species returned to the upper reach for reproducing.Studies on the past distribution of the fish before the time when the Gezhouba Dam was constructed found that Chinese sucker must be a fish living mainly in the upper reach of Yangtze river basin (the section from Three Gorges up to Yibin City).Only some adult fish or larvae hatched in lower section of the upper reach of the basin migrate to the middle and lower reaches;and then,come back to the upper reach before about 4 years old.
Two respective populations exist in the upper and lower Gezhouba dam at present and they can reproduce separately.The survival of the species has not been affected by in the course of dam construction including the Dam of Sanxia Gorges.After completion of the constructions,currents slow down or even remain still in many places together with increase in transparency and flourishing in zoobenthos etc.in the reservoir.The fish like to feed on zoobenthos and like to stay in slow or still waters.So the changes in these natural conditions are likely to be beneficial to growth of Chinese sucker,adult and larvae alike.