球形棕囊藻对五种水生动物的急性毒性作用

Acute Toxicities of Phaeocystis globosa on Five Aquatic Animals

利用室内半静水法研究球形棕囊藻培养液、藻细胞悬浮液、去藻细胞滤液、藻细胞内容物、藻细胞碎片以及溶血毒素粗提物对卤虫(Artemia sinica)、褶皱臂尾轮虫(Brachionus plicatilis)、蒙古裸腹溞(Moina mongolia)、赤点石斑鱼幼鱼(Epinephelus akaara)和南美白对虾(Penaeus vannamei)5种水生动物的影响,并对其致毒途径进行分析。结果表明,与对照相比,培养液、藻细胞悬浮液处理卤虫,其运动速度下降,培养液、藻细胞悬浮液与毒素粗提物处理轮虫72h,存活率显著降低(P<0.05),卤虫、轮虫消化道中充满藻细胞,提示摄食球形棕囊藻可能是引起卤虫、轮虫中毒的主要途径。培养液、滤液和藻细胞内容物对赤点石斑鱼幼鱼均有显著的致死作用,而藻细胞碎片和溶血毒素粗提物对幼鱼的存活无明显影响,表明球形棕囊藻细胞表面并不存在毒性物质,球形棕囊藻可能会分泌有毒物质进入水体,进而影响鱼类的生长。培养液、藻细胞悬浮液、去藻细胞滤液、毒素粗提物处理蒙古裸腹溞72h虽有死亡,但存活率与对照无显著差异;南美白对虾的情况与蒙古裸腹溞类似,表明球形棕囊藻及相关组分对蒙古裸腹溞和对虾的影响较小。这些结果表明,球形棕囊藻对不同生物的毒害作用不同;摄食和分泌有毒、有害物是球形棕囊藻引致生物中毒的主要途径;除了溶血毒素以外,球形棕囊藻还可能产生其他鱼毒性物质。

The acute toxicities of P. globosa on Artemia sinica, Brachionus plic atilis, Moina mongolia, Epinephelus akaara and Penaeus vannamei were studied using the method of semi-static water, and the poisoning route were discussed. P. globosa had different toxicity on the five aquatic animals. The survival of B. plicatilis decreased significantly （P 〈 0.05） in algal culture, re-suspension and hemolytic toxins extraction of P. globosa for 72 h, whereas only motility of A. sinica was slightly inhibited by algal culture and re-suspension. Many algal cells in the alimentary canal of A. sinica and B. plicatilis, it suggested P. globosa cell could be fed by them. The algal culture, ceU-free medium and cell contents had remarkable effects on the survival of larval E. akaara, but not cell fragments and hemolytic toxins extract of P. globosa, which implied that harmful substances were not attached to the algal cell surface, but inside the algal cell, and that P. globosa could excrete other harmful substances than hemolytic toxins into water to imperil surrounding organisms. After exposured in algal culture, re-suspended cells, filtrate and hemolytic toxins from P. globosa for 72 h, respectively, motilities of M. mongolia were all slightly different from the control though some M. mongolia died during the course. The P. vannamei, exposured in components from P. globosa algal culture for 72 h, were similar to M. mongolia. These suggested that P. globosa had few negative impacts on the survival of M. mongolia and P. vannamei. In conclusion, P. globosa had different effects on various aquatic animals by being ingested or excreting harmful materials into the water.