Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, People's Republic of China.
Arch Environ Contam Toxicol. 2010 Jan;58(1):140-50. doi: 10.1007/s00244-009-9348-1. Epub 2009 Jun 6.
This study investigated the zinc toxicity to red sea bream Pagrus major embryos and larvae at 18 +/- 1 degrees C (33 +/- 1 per thousand in salinity) under laboratory conditions. The acute toxicity tests indicated that zinc 48-h LC50 to embryos and 96-h LC50 to larvae were 4.3 (3.3-6.3; 95% confidence limits) and 10.1 (9.0-11.4) mg l(-1), respectively, suggesting that embryos were more sensitive than larvae to zinc exposure. The subchronic toxicity test, in which embryos and larvae were continuously exposed to 0, 0.1, 0.3, 0.5, 0.7, 1.0, 1.5, 2.0, and 2.5 mg Zn2+ l(-1) solutions for 10 days, demonstrated that waterborne zinc had distinctly toxic effects on the development, growth, and survival of red sea bream embryos and larvae. Zinc exposure at concentrations > or = 0.5 mg l(-1) would lead to a low hatching rate (19-78%, vs. 98% in controls), high mortality (29-91%, vs. 10% in controls), and morphological abnormality (12-77%, vs. 0.3% in controls) in embryos and larvae, while it caused delay in time-to-hatch in embryos at concentrations > or = 1.0 mg l(-1). These four biological parameters were zinc concentration dependent and could be effective bioindicators for evaluating the toxicity of zinc to the early life stage of this fish. Heartbeats of embryos (9-13 beats 10 s(-1)) were relatively low and were not significantly influenced by zinc concentration, although they rose remarkably with elevated zinc concentration in larvae at the end of the test, particularly when it was > or = 1.0 mg l(-1) (36-38, vs. 31 beats 10 s(-1) in controls). The total length (LT) of the larvae at the end of the test was reduced by 12.2% and 15.6% in the 1.0 and 2.0 mg l(-1) solutions but did not vary significantly in other solutions in comparison with the controls. Heartbeat and LT were less sensitive to zinc exposure and might not be good biological parameters for determining the toxicity of zinc to the early life stage of red sea bream.
本研究在实验室条件下，于 18±1°C（盐度为 33±1‰）下研究了锌对红鲷鱼胚胎和幼鱼的毒性。急性毒性试验表明，锌对胚胎的 48 小时 LC50 和对幼鱼的 96 小时 LC50 分别为 4.3（3.3-6.3；95%置信限）和 10.1（9.0-11.4）mg l(-1)，表明胚胎对锌暴露比幼鱼更敏感。在亚慢性毒性试验中，将胚胎和幼鱼连续暴露于 0、0.1、0.3、0.5、0.7、1.0、1.5、2.0 和 2.5 mg Zn2+ l(-1)溶液中 10 天，结果表明，水中的锌对红鲷鱼胚胎和幼鱼的发育、生长和存活有明显的毒性作用。锌暴露浓度≥0.5mg l(-1)会导致孵化率降低（19-78%，对照组为 98%）、死亡率升高（29-91%，对照组为 10%）和形态异常（12-77%，对照组为 0.3%），同时在浓度≥1.0mg l(-1)时会延迟胚胎孵化时间。这四个生物学参数与锌浓度呈依赖性关系，可作为评价锌对该鱼早期生活阶段毒性的有效生物指标。胚胎的心跳（9-13 次 10 s(-1))相对较低，且不受锌浓度的影响，尽管在试验结束时，尤其是在浓度≥1.0mg l(-1)时，幼鱼的心跳明显升高（36-38 次 10 s(-1)，对照组为 31 次 10 s(-1)）。试验结束时，幼虫的全长（LT）分别减少了 12.2%和 15.6%，而在 1.0 和 2.0 mg l(-1)溶液中与对照组相比，其他溶液中的 LT 变化不显著。心跳和 LT 对锌暴露的敏感性较低，可能不是确定锌对红鲷鱼早期生活阶段毒性的良好生物学参数。
