Biological zero point of gonad development of Ruditapes philippinarum

We have conducted an artificial promoting nature experiment on Ruditapes philippinarum from Dalian and Fujian province in artificial condition in 2004 and 2005; observed and recorded the average daily temperature and the laying of egg and sperm. Thereby,with the mathematical statistics methods and formula K= H (T-t) thermal sum beneficial,it is indicated that the biological zero point for the gonad development of Ruditapes philippinarum from Dalian is 6.774℃,and that from Fujian province is 10.990℃. The histological observation demonstrates that the average water temperature for half of Ruditapes philippinarum from Dalian and Fujian to enter into multiplication period is 7.0℃ and 10.1℃,respectively. Therefore,it is verified from the experiment that the biological zero points for the gonad development of Ruditapes philippinarum from the north and south sea areas are different.