阿特拉津和林丹对紫贻贝生长与繁殖净能的影响

摘要

The present investigation was undertaken to determine physiological responses of the marine mussel, Mytilus edulis L. , to sub-lethal concentrations of lindane (1/2 LC50 for 60 days; 0.935 mg/L) and atrazine (1/2 LC50 for 60 days; 3. 585 mg/L), both of which have priority status as environmental pollutants. Both pesticides after 56 days of exposure showed bioaccumulation factors which were consistent with their partitioning properties, with lindane accumulating to a higher concentration (372 μg/g dry weight) than atrazine (137 μg/g dry weight). Oxygen consumption in mussels exposed to lindane (0.935 mg/L) for 56 days fell to 10% of control levels, whereas with exposure to atrazine (3.585 mg/L) at the same exposure time the oxygen consumption was elevated to 29 % compared with controls. Ammonia ex cretion increased with exposure to lindane and atrazine. However, both pesticides reduced feeding rate and absorption ef ficiencies. Lindane reduced feeding rate, oxygen consumption, ammonia excretion, food absorption efficiency, and scope for growth. Atrazine produced a profile of effects on activity which was different from that observed with lindane: it depressed feeding rate and food absorption efficiency, but in contrast to lindane it increased oxygen consumption and ammonia excretion. Overall, it induced a marked reduction in the scope of growth (SFG). Toxicological symptoms ob served in atrazine treated mussels contrasted with those of animals exposed to lindane. The physiological responses of mus sels, when complemented with chemical analysis of mussel tissues provides a powerful monitoring tool. The results of this present study indicate that two months of exposure to 1/2 LC50 of lindane or atrazine was sufficient not only to allow the accumulation of lindane or atrazine within the animal' s tissues but also for physiological changes to be made in response to these accumulations [Acta Zoologica Sinica 52 (4) : 712 - 723, 2006].%本研究评估了亚致死浓度的林丹(1/2的60 d-LC50,0.935 mg/L)和阿特拉津(1/2的60 d-LC50,3.585 mg/L)对海洋性贝类影响的生理学反应.林丹和阿特拉津是已被公认的环境污染物质.56 d的实验表明,这两种农药在贝类体内具有积累作用,而且在体内各器官的积累程度与其作用的靶器官相一致.林丹在体内的积累浓度(每克干重372μg)比阿特拉津(每克干重137μg)更高.该贝类在林丹中暴露56 d,其氧的消耗比对照组降低10%,而在阿特拉津中则比对照组提高了29%.经林丹和阿特拉津暴露后,增加了氨排泄物.但是,两种农药均使贝类的取食率和吸收率下降.林丹会降低贝类的取食率、氧消耗、氨排泄、食物吸收率以及生长范围.在形式上,阿特拉津对贝类的影响与林丹的影响有不同之处,它会降低贝类的取食率和食物吸收率,但与林丹不同的是,它会提高贝类的氧消耗和氨排泄.总之,阿特拉津会明显地减小贝类繁殖净能.因此,阿特拉津暴露与林丹暴露的毒性症状是一致的.结合组织化学分析,贝类的生理学反应可作为一种理想的环境监测工具.研究结果表明,在二分之一的半致死浓度下暴露两个月,不仅能有效地证明林丹和阿特拉津在贝类组织内具有积累作用,而且对这些积累能产生生理反应[动物学报 52(4):712-723,2006].