摘要
本文利用原子吸收分光光度法研究镉暴露实验中海湾扇贝不同器官组织富集、排放镉的过程及影响因素。水体中镉通过被动扩散进入海湾扇贝鳃,根据吸附等温线并结合直线拟合结果得海湾扇贝鳃对镉的单层饱和结合量为2.12μmol.g干重。鳃对镉的富集量和富集速率与水相中镉浓度成正相关关系,最高浓度组(2μmol.L-1)的镉富集量和富集速率分别为(1.5±0.52)μmol.g-1干重和(0.375±0.13)μmol.(g.d)-1。随着养殖时间的延长,海湾扇贝鳃、内脏和肌肉镉富集量逐渐增加,14d(336h)后,内脏和鳃中镉富集达到平衡,但肌肉中镉富集是否达到平衡,尚需进一步研究。盐度对海湾扇贝鳃、内脏和肌肉镉富集速率无显著影响(P>0.05)。富集在海湾扇贝体内的镉不断被排出,其中鳃的排放率最大,达到了38.3%,其次是内脏、肌肉。
Cadmium is ubiquitous in the human environment and has been recognized as one of the most deleterious heavy metal pollutants. Pollution of sea by cadmium as a component of industrial wastes leads to a considerable increase in its concentration in aquatic animals. But, considerable difference in the sensitivity to cadmium among shellfish has been reported. This work was an attempt to investigate cadmium bioaccumulation in various tissues of bay scallop Argopecten irradians and the factors influencing cadmium bioaccumulation during simulated pollution. Cadmium in the seawater entered the gill of bay scallop by passive pervasion. The Langmuir isothenns were employed to describe the gill surface binding activity of cadmium. The binding capabilities were 2.12 μmol·g^-1 dry wt. The cadmium exposure results indicate： the bioaccumulation amount in tissues increased with the addition of cadmium concentration in seawater. When the cadmium concentration in the seawater was 2 μmol·L^-1, after 4 days, the bioaccumulation amount in the gill was （1.5±0.52）μmol·g^-1 dry wt and the accumulation velocity was （0.375±0.13） μmol （g·d）^-1. Atthe same time, the bioaccumlation amount in the viscera was （7.19±0.83） μmol·g^-1 dry wt and the accumulation velocity was （1.79±0.21）μmol（g·d）^-1. But the accumulation number in the muscle was the least [（0.005 ±0.0009） μmol·g^-1 dry wt]. During of 19 days exposure in seawater containing 2 μmol·L^-1 cadmium the bioaccumulaton in the gill,viscera and muscle increased with the extension of feeding time. After 14（336 h）days, the cadmium accumulation in the gill, viscera was close to saturation. But the cadmium in the muscle was far from saturation. In fact, when the storage capacity limits of the liver and kidney are reached, cadmium accumulation in muscle is stimulated. The reported results show that salinity affects cadmium accumulation in various tissues of the tropical fiddler crab Uca rapax. In the present study, we found that there was not significant effects of salinity on cadmium accumulation in various tissues of Argopecten irradians（ P 〉 0.05）. When the bay scallop was bred in unchlorinated, aerated well water, the cadmium accumulated in the body was eliminated significantly. The excretion rate in the gill was 38.3 %.
出处
《水产学报》
CAS
CSCD
北大核心
2006年第6期801-805,共5页
Journal of Fisheries of China
基金
"十五"国家重大科技专项(2001BA804A29)
农业部海洋渔业资源可持续利用重点开放实验室开放课题(实开2005-02)
关键词
海湾扇贝
镉
富集
排放
Argopecten irradians
cadmium
bioaccumulation
excretion
