Anderson B S, Hunt J W, Piekarski W J, Phillips B M, Englund M A, Tjeerdema R S, Goetzl J D
Institute of Marine Sciences, University of California, Santa Cruz 95064, USA.
Arch Environ Contam Toxicol. 1995 Oct;29(3):366-72. doi: 10.1007/BF00212502.
Performance of a 7-d growth and survival toxicity test protocol using larval topsmelt, Atherinops affinis (Ayres), was evaluated for copper chloride and sodium azide at representative estuarine salinities. Results showed that topsmelt are amenable to toxicity testing at estuarine salinities ranging from 5 to 34/1000 since control survival was 100% in all toxicity tests. Sensitivity to both toxicants increased at lower salinities, with the LC50s for copper ranging from 205 micrograms/L at 34/1000 to 44 micrograms/L at 10/1000, and those for sodium azide ranging from 54 mg/L at 34/1000 to 7 mg/L at 5/1000. Larval tissue osmolality decreased with increasing copper concentration relative to control fish. Copper uptake was not affected by changes in salinity. This suggests that increased sensitivity to copper was due, in part, to the increasing physiological challenge of osmoregulation. It is also possible that cupric ion concentration increased at lower salinities, resulting in reduced larval survival. It is hypothesized that increased sensitivity to azide at lower salinity was due to the interaction between azide toxicity and increasing osmotic challenge. A second experiment with azide showed that larval acclimation time did not affect the interaction between salinity and azide toxicity.
采用河口代表盐度，对使用银汉鱼（Atherinops affinis，艾尔斯）幼体进行的为期7天的生长和存活毒性试验方案，针对氯化铜和叠氮化钠进行了评估。结果表明，银汉鱼适合在盐度范围为5至34‰的河口盐度下进行毒性测试，因为在所有毒性试验中，对照组的存活率均为100%。在较低盐度下，对两种毒物的敏感性均增加，铜的半数致死浓度（LC50）范围为：在34‰时为205微克/升，在10‰时为44微克/升；叠氮化钠的半数致死浓度范围为：在34‰时为54毫克/升，在5‰时为7毫克/升。相对于对照鱼，幼体组织渗透压随铜浓度增加而降低。铜的摄取不受盐度变化的影响。这表明对铜敏感性增加部分是由于渗透调节生理挑战的增加。也有可能在较低盐度下铜离子浓度增加，导致幼体存活率降低。据推测，在较低盐度下对叠氮化钠敏感性增加是由于叠氮化钠毒性与渗透压挑战增加之间的相互作用。关于叠氮化钠的第二项实验表明，幼体适应时间不影响盐度与叠氮化钠毒性之间的相互作用。
