The biological zero of gonadal development and the effective accumulated temperature of one and two-year-old razor clams Sinonovacula constricta(Lamarck 1818)were studied in Sanmen County,Zhejiang Province,China betwe...The biological zero of gonadal development and the effective accumulated temperature of one and two-year-old razor clams Sinonovacula constricta(Lamarck 1818)were studied in Sanmen County,Zhejiang Province,China between April 2016 to October 2017,using a new variety named“Shen-Zhe No.1”.The biological zero was determined by using the rule of effective accumulated temperature and the linear regression method,which was confirmed using a histological analysis of the full gonadal development cycle.The results showed that the biological zero of gonadal reproduction of 1-year-old and 2-year-old S.constricta was the same:20.8℃.When the temperature reached 20–21℃,analysis of the histological sections indicated that more than half of the S.constricta individuals initiated gonadal development.The average effective accumulated temperature over two years was 806 d℃.This study contributes to our understanding of the regulation and control of gonadal maturation,suggesting that changes in the spawning and breeding season during one-year of farming using the new variety of razor clam could provide an economic benefit to industrialized large-scale spat production.The results demonstrated that the razor clam S.constricta is a typical clam of the accumulative temperature mature oviposition type.In addition,although S.constricta does not display hypothermy,it requires a lower temperature for gonadal maturity and spawning.展开更多
基金This work was supported by the National High-tech R&D Program(863 Program)(863 Program)of China[grant number 2012AA10A400]the Shanghai Universities First Class Disciplines Project of Fisheries,and the Shanghai Universities Knowledge Service Platform[grant number ZF1206].
文摘The biological zero of gonadal development and the effective accumulated temperature of one and two-year-old razor clams Sinonovacula constricta(Lamarck 1818)were studied in Sanmen County,Zhejiang Province,China between April 2016 to October 2017,using a new variety named“Shen-Zhe No.1”.The biological zero was determined by using the rule of effective accumulated temperature and the linear regression method,which was confirmed using a histological analysis of the full gonadal development cycle.The results showed that the biological zero of gonadal reproduction of 1-year-old and 2-year-old S.constricta was the same:20.8℃.When the temperature reached 20–21℃,analysis of the histological sections indicated that more than half of the S.constricta individuals initiated gonadal development.The average effective accumulated temperature over two years was 806 d℃.This study contributes to our understanding of the regulation and control of gonadal maturation,suggesting that changes in the spawning and breeding season during one-year of farming using the new variety of razor clam could provide an economic benefit to industrialized large-scale spat production.The results demonstrated that the razor clam S.constricta is a typical clam of the accumulative temperature mature oviposition type.In addition,although S.constricta does not display hypothermy,it requires a lower temperature for gonadal maturity and spawning.
