Cu2+、Zn2 、Pb2 对七带石斑鱼(Epinephelus septemfasciatus)胚胎和初孵仔鱼的毒性效应

The toxic effects of Cu2+, Zn2 , and Pb2 on the embryos and larvae of Epinephelus septemfasciatus

中文关键词: 七带石斑鱼  金属离子  胚胎  仔鱼  毒性效应

英文关键词: Epinephelus septemfasciatus  Metal ions  Embryos  Larvae  Toxic effects

中文摘要:

      在(21.0±0.5)℃条件下，研究了Cu2+、Zn2 、Pb2 3种金属离子对七带石斑鱼胚胎和初孵仔鱼的毒性效应。结果表明：1) 随着3种金属离子浓度的升高，受精卵的孵化速率和孵化率逐渐降低，畸形率逐渐增加。重金属引发胚胎发育发生各种畸形，如胚体增生异常而死亡、尾芽弯曲，仔鱼不能正常出膜而死亡，初孵仔鱼脊椎弯曲多呈L、S、V型或尾部未展开呈逗号状畸形。综合孵化速率、孵化率和畸形率等指标，可以看出，3种金属离子对胚胎发育的毒性大小依次为Cu2 > Zn2 > Pb2 ；2) 初孵仔鱼的毒性试验周期为96 h，随着时间加长，仔鱼的存活率逐渐降低，且金属离子浓度越大，其下降幅度越大。此外，仔鱼出现脊椎S、V型弯曲等畸形也越来越多。通过计算各时间段的半致死浓度(LC50)和安全浓度得出，3种金属离子对初孵仔鱼的毒性大小依次为Cu2 > Pb2 > Zn2 。本研究的一系列数据可以为新渔业水质标准的制定和水环境的监测提供理论参数，为七带石斑鱼等鱼类繁育养殖中的重金属监测与治理提供重要科学依据。

英文摘要:

      The current study investigated the toxic effects of Cu2+, Zn2 , and Pb2 on the embryos and larvae of Epinephelus septemfasciatus. The results indicated that as the three heavy metals ion levels increased the fertilized egg hatching speed and the hatching rate gradually declined while the malformation rate gradually increased. The malformation of the embryos and larvae included bended tail sprouts, incomplete hatching, the “L”, “S” and “V”-shaped vertebrate of newly-hatched larvae and comma-shaped un-expanded tail deformity. Based on the comprehensive hatching rate, hatching rate and malformation rate, the toxicity to the embryonic development of these heavy metal ions were: Cu2 > Zn2 > Pb2 . The newly-hatched larvae toxicity test cycle was 96 h. The survival rate of the larvae gradually reduced with the increased time. The increased concentrations of these heavy metal ions dramatically decreased the survival rate while increased the number of deformity. Based on the time period of the half lethal concentration (LC50) and the safety concentration, the toxicity of three heavy metal ions on the newly-hatched larvae were: Cu2 > Pb2 > Zn2 . These results may contribute to the formulation of new fishery water quality standard and parameters of water environment monitoring and provide important scientific basis for E. septemfasciatus breeding of heavy metal monitoring and management.