浒苔腐烂液的生物毒性及其对太平洋牡蛎胚胎发育的影响

为防范浒苔绿潮次生灾害和降低海水养殖风险,文章采用人工授精的太平洋牡蛎胚胎、不同相对浓度的浒苔腐烂液以及基于发光细菌的生物毒性检测法,通过实验分析浒苔腐烂液的生物毒性及其对太平洋牡蛎胚胎发育的影响。研究结果表明:随着浒苔腐烂液相对浓度的提高,太平洋牡蛎D形幼虫相对孵化率逐渐降低至0,滞育和畸形等非正常胚胎增多,囊胚-原肠期和担轮幼虫期占比降至极低,易发生卵膜破裂和卵裂球分散,这些与太平洋牡蛎胚胎发育的阶段特点和浒苔腐烂液生物毒性的作用机制等有关;浒苔腐烂液相对浓度(0.25～10g/L)与生物毒性呈显著正相关,生物毒性(10%～97%)与相对孵化率呈显著负相关,且生物毒性达重毒水平时(由56%至70%)相对孵化率大幅下降(由66%至18%);建议在太平洋牡蛎胚胎发育的相对孵化率为50%时发出浒苔绿潮的渔业高风险预警,对应的浒苔腐烂液相对浓度为4.6g/L、生物毒性为55%。

Biotoxicity of Ulva prolifera Decomposing Solution and Its Effect on the Embryonic Development of Crassostrea gigas

To prevent the secondary toxic hazard of Ulva prolifera Green tide and reduce the risk of mariculture,the biotoxicity of U.prolifera decomposing solution and its effect on the embryonic development of Crassostrea gigas were studied.The fertilized eggs within 1 h after fertilization were taken as the experiment subjects while determining the biotoxicity by luminous bacteria method.The results showed that the biotoxicity was obviously increased with increasing decomposing solution concentration.At the same time,diapauses and deformities were more serious and the relative hatching rate was decreased gradually.The higher the concentration of decomposing solution was,the higher risk of egg membrance ruptured and blastomere scattered.They were related to the characteristics of embryonic development of C.gigas and the effect of secondary toxicity caused by decomposing solution.There was a significant positive correlation between the relative concentration of U.prolifera decomposing solution (0.25 to 10 g/L) and the biotoxicity,and a strong negative correlation between the biotoxicity (10% to 97%) and the relative hatching rate.When the biotoxicity increased from 56% to 70%,the relative hatching rate decreased from 66% to 18%.In order to effectively prevent the secondary toxicity caused by U.prolifera decay,it is suggested to take the 50% relative hatching rate of C.gigas as the warning value,when the corresponding concentration was 4.6 g/L and the biotoxicity was 55%.