 The Chinese sturgeon is the largest fish in the river and among the largest freshwater fish in the world, reaching a length of ; the extinct Chinese paddlefish reputedly reached as much as , but its maximum size is labeled with considerable uncertainty.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.