The Study About The Coilia Nasus From Ming And Qing Dynasty In The Middle And Lower Yangtze Area.

This paper focuses discussion on the changes of population resources,include distribution of Coilia nasus,the time of the fish anadromous migration for spawning and the evolution of spawning ground.Meanwhile,the study distinguish coilia nasus' s synonym by combing the local chronicles.The results show that coilia nasus was abundant before 1970's,as evidenced by the large distribution of Coilia nasus and the large and many of spawning ground during the Ming dynasty to the Republic of China.In 1973,each province located along to the middle and lower Yangtze area catches reached the historical high,because of abundant population foundation,superior natural factors and overfishing.But,the catches kept reducing after 1973.There are reasons as follow: excess catches vibrate fundamentally population structure in 1973,Coilia nasus get smaller gradually by constantly overfish and artificial destruction,the number and area of spawning ground was seriously reduced.So,thereafter catches was never return to 1973 again.