鲮体内组织和养殖水体中重金属分布及相关性研究

Distribution and Correlation of Heavy Metals in Tissues of Cirrhinus molitorella and in Culture Pond Suspended Solids and Sediment

研究鲮体内组织和养殖水体中重金属分布并进行相关性分析,为鲮生态养殖研究提供基础参考数据。2015年5、7、9和11月,采集鲮养殖池塘内悬浮物、沉积物以及鲮的呼吸树、大肠、小肠、肠内物、纵肌、体壁组织,测定Cr、Hg、Cd、Pb、As、Cu、Ni等7种重金属含量,数据采用软件Origin 7.0分析,显著性差异比较采用ANOVA法和Tukey多重比较法。结果显示,肠内容物中Cu、Cd、Pb、Cr、Ni、As、Hg含量均最高（P〈0.05）,范围为0.03-0.73 mg/kg;悬浮物和沉积物的Hg含量在4个月份的分布均差异显著（P〈0.05）,在沉积物含量范围为0.01-0.22 mg/kg,在悬浮物含量范围为0.07-1.88 mg/kg,而其他6种重金属含量差异不显著（P〉0.05）;体壁与肠内容物、肠内容物与悬浮物、悬浮物与沉积物之间的重金属含量均显著相关（P〈0.05）,相关系数分别为0.893、0.826、0.851。鲮养殖塘内的悬浮物重金属是经过沉降作用逐渐富集到底质,鲮的消化道吸收是其体内重金属积累主要方式,水中悬浮物对鱼肠内重金属污染特征起到了关键作用,鲮养殖水体中生物相与非生物相的重金属含量的分布具有规律性。

Cirrhinus molitorella is an important freshwater fish species cultured in southern China and is favored by farmers and customers for its high profit and good flavor. Aquatic product safety has become a concern because the contamination of waters in rivers and culture ponds is intensified by industrial and agricultural production,and extensive in fish culture. Therefore,the study of ecological breeding of C. molitorella is significant for improving the quality and expanding the market consumption of C. molitorella. In this study,the contents of seven heavy metals in the tissues of C. molitorella,and suspended particles and surface sediment of the culture pond were investigated.The correlations between them were analyzed,aiming to explore the mechanism of heavy metal intake by C. molitorella and provide basic reference data for the ecological breeding of C. molitorella. In May,July,September and November of 2015,samples of suspended solids,sediments and C. molitorella were collected in triplicate from the demonstration culture pond of C. molitorella at an aquaculture company in Nanning of Guangxi Province,with 10-20 C. molitorella specimens collected each time. The contents of Cu,Cd,Cr,Pb,Ni,Hg and As in the suspended solids and sediment of the culture pond and tissues of C. molitorella（ respiratory tree,large intestine,small intestine,intestinal content,longitudinal muscle and body wall） were determined. The contents of the seven heavy metals in the respiratory tree,large intestine,small intestine,longitudinal muscle and body wall of C. molitorella were not significantly different,but the heavy metal concentration in the intestinal contents were significantly higher than those of other tissues（ P〈0. 05）,ranging from 0. 03 to 0. 73 mg/kg（ P〈0. 05）. The content of Hg varied significantly among the four months of the investigation（ P〈0. 05）,ranging from 0. 01-0. 22 mg/kg in the sediments and 0. 07-1. 88 mg/kg in the suspended particles,while the concentrations of the other six heavy metals were not significantly different over the four months（ P〉0. 05）. The correlations of heavy metal content between the body wall and intestinal contents,the intestinal contents and suspended particles,and suspended particles and sediments were strongly correlated（ P〈0. 05）,with correlation coefficients of 0. 893,0. 826,0. 851,respectively. The movement of heavy metals among different phases can be summarized as follows. Heavy metals in suspended particles are deposited to sediments and absorption in the intestinal tract is the primary route for heavy metal accumulation in C. molitorella. Suspended particles play a key role in the heavy metal contamination of C. molitorella. The regular distribution pattern of heavy metals in biological and non-biological phases provides an important insight for the ecological breeding of C. molitorella.