盐度对香港巨牡蛎摄食和代谢的影响

为了探明香港巨牡蛎(Crassostrea hongkongensis)的摄食和代谢与盐度的关系,在实验室条件下采用流水系统研究了不同盐度(S)条件下香港巨牡蛎的滤水率(FR)、摄食率(IR)、吸收率(AE)、耗氧率(OR)和排氨率(NR)的变化规律。结果显示:在盐度6～27范围内,盐度对香港巨牡蛎的滤水率、摄食率的影响都极显著,随着盐度的升高,滤水率与摄食率先增大后减小,盐度13时最大,分别为5.93 L/g.h和38.26×106cell/g.h;盐度对吸收率的影响不显著,吸收率为74.77%～78.41%。盐度对香港巨牡蛎的耗氧率和排氨率的影响极显著,随着盐度的升高,耗氧率与排氨率先增大后减小,盐度20时最大,分别为1.76 mg/g.h和0.11 mg/g.h;盐度对O∶N比的影响不显著,不同盐度下O∶N平均值为17.89,表明在本试验条件下香港巨牡蛎代谢所需要的能量主要由脂肪和碳水化合物提供。根据研究结果可以判断,香港巨牡蛎的摄食和代谢活动在盐度13~20之间处于较适宜水平。

Effect of salinity on the feeding and metabolic physiology of Crassostrea hongkongensis

In order to make clear the relationship between salinity and the feeding,metabolic physiology of Crassostrea hongkongensis,the variation of filtration rate(FR),ingestion rate(IR),absorption efficiency(AE),oxygen consumption rate(OR) and ammonia excretion rate(NR) under different salinity(S) were studied at laboratory conditions using a running water system.The results showed that,in the context of salinity 6~27,the salinity had a very significant effect on filtration rate and ingestion rate.The filtration rate and ingestion rate were the highest at the salinity of 13,respectively 5.93 L/g·h and 38.26×106 cell/g·h,and decreased at the higher and lower salinity.The salinity had no significant impacts on absorption efficiency of C.hongkongensis,witch was between 74.77%～78.41%.The salinity had a very significant effect on oxygen consumption rate and ammonia excretion rate of C.hongkongensis.The oxygen consumption rate and ammonia excretion rate were the highest at the salinity of 20,respectively 1.76 mg/g·h and 0.11 mg/g·h,and decreased at the higher and lower salinity.The salinity had no significant impacts on the O∶N.The values of O∶N ratios were 17.89,which indicated that the C.hongkongensis in the experiment mainly utilized carbohydrate and lipid as their energy sources.It could be judged based on the results that the feeding and metabolism of C.hongkongensis were at a appropriate salinity level among 13 to 20.