DISCUSSION ON THE GONADAL DEVELOPMENT AND DEGENERATION OF CHINESE STURGEON, ACIPENSER SINENSIS

Chinese sturgeon (Acipenser sinensis), a critically endangered and iconic species in the Yangtze River, failed to breed in recent years, making this species on the brink of extinction. The causes of breeding failure remains controversial. Huang, et al. proposed that the construction of Gezhouba Dam was the main factor that resulted in serious gonadal degeneration of the mature Chinese sturgeon, ultimately leading to its sharp population decline. Besides, they also claimed that “the methods and materials of the research performed by Institute of Hydrobiology, Chinese Academy of Sciences (IHB) to deny the concept of gonadal degeneration of Chinese sturgeon are inadequate and unreliable”. In order to prevent this wrong conception from misleading conservation for Chinese sturgeon, here we refuted this wrong conception by analyzing the following aspects: the gonadal development and degradation criteria, life history stages and gonadal status of Chinese sturgeon, as well as the effects of Gezhouba Dam and Three Gorges Dam on the spawning activities. Our analysis indicated that Ke, et al. misjudged the normally developed stage Ⅲ gonad of Chinese sturgeon as “degenerated gonad”. Their viewpoint that the gonads of adult sturgeons started to degenerate quickly after entering the Yangtze was also wrong because the viewpoint obviously departed from the common law of gonadal development of Chinese sturgeon. By analyzing long-term monitoring data, we demonstrated that the spawning dates and the gonadal maturation ratio of the spawning stock did not change significantly after the migration distance was shorter due to the construction of Gezhouba Dam. The effective breeding model proposed and constructed by Huang, et al. is completely erroneous because they distortedly interpreted and used the data from previous studies. Their model is only a mathematical game created by people without fish biological knowledge. Although the current protection of Chinese sturgeon is challenging, we believe that the population of this species will be recovered if we can reduce human activities in the spawning area, take more effective actions to restore the spawning ground and the breeding conditions, and release more big-size individuals when accompanying with the implementation of ten-years fishing ban in the Yangtze River.