广东流沙湾5种贝类的δ^(13)C值和δ^(15)N值研究

A study on the δ^(13)C and δ^(15)N values of five bivalves in Liusha Bay

广东流沙湾海水养殖业发达,尤其是贝类增养殖已成为当地的支柱产业.但近年来其养殖环境的恶化对贝类产品的安全输出造成了越来越严重的影响,利用稳定同位素技术研究贝类的新陈代谢过程可为贝类增养殖提供较先进的基础数据.本研究选取流沙湾的5种重要养殖贝类,对其肌肉组织、鳃、外套膜和内脏囊分别进行稳定碳、氮同位素测定分析.结果表明,贝类δ13C值的范围是-19.14‰～-15.11‰,δ15N值的范围是6.10‰～10.57‰.从大小、组织、种类三方面比较5种贝类的稳定碳氮同位素比值,可得出如下结论:同种贝类,大小不同,其δ13C、δ15N值大都随壳长、壳重的增大而减小,但翡翠贻贝(Pernaviridis)的δ13C值和墨西哥湾扇贝(Argopecten irradians concentricus)的δ15N值则相反,无论大、小组之间δ13C、δ15N值的变化是增大还是减小,幅度均不超过1.00‰;同种贝类,组织不同,其δ13C、δ15N的最小值均为内脏囊,δ13C的最大值不定,δ15N的最大值也是内脏囊;相同组织,不同贝类,其δ13C、δ15N值的大小排列顺序各不相同,无统一规律,但华贵栉孔扇贝(Chlamys nobilis)的δ13C值均小于墨西哥湾扇贝,而马氏珠母贝(Pinctada martensii)的δ15N值均小于企鹅珍珠贝(Pteria penguin).由研究数据可推知流沙湾双壳贝类的物质与能量流动途径基本是由内脏囊到外套膜和鳃,最后到肌肉.

Seawater aquaculture develops well in Liusha Bay of Guangdong province,especially bivalve production which has become an important industry locally.However,in recent years,a output of bivalve products becomes increasingly unstable because of deteriorative breeding environment.The study of metabolism process of bivalve with stable isotope technology can provide advanced data for bivalve breeds.In this study,the muscle,gills,mantle and visceral mass of 5 important breeding bivalves were tested by Stable Isotope Ratio Mass Spectrograph.The results showed that δ13C and δ15N values of the bivalve were measured between-19.14‰ and-15.11‰,and between 6.10‰ and 10.57‰,respectively.Compared with the size,tissues and the species,it shows that with the growth of 5 species the ratios of stable carbon isotope,δ13C and δ15N,decreased with the weight and size of the shells.However,the range of δ13C of Perna viridis and the δ15N of Argopecten irradians concentricus changed less than 1.00‰ whatever δ13C and δ15N fluctuated.Secondly,in the same species,the minimum δ13C and δ15N is always located at the visceral mass in spite of the variation of maximum δ13C.Thirdly,in the same tissue there was no a regular consequence for the value of δ13C and δ15N among the species except that the averaged δ13C from Chlamys nobilis is less than that of Argopecten irradians concentricus and that the averaged δ15N of Pinctada martensii is less than that of Pteria penguin.Finally,the values of δ increased in a sequence of visceral mass,mantle,gills then to muscle,which may have followed the ways of matter-energy flows.