塔玛亚历山大藻对鲈鱼幼鱼毒性效应研究

塔玛亚历山大藻（Alexandrium tamarense)(ATHK)藻液能对鲈鱼（Lateolabrax japonicus)幼鱼（2．5cm）的存活有明显的影响，96h的半致死浓度为4000cells/mL。根据该藻PSP产毒量37．48fmol/cell（毒性为11pg(STX eq)/cell）计算，鲈鱼幼鱼的96h半致死藻毒素浓度相当于149．92fmol/L（毒性为44pg（STX eq)/L）。通过对塔玛亚历山大藻藻液各组分（都相当于8000cells/mL）：藻细胞悬浮液、去藻过滤液、细胞内容物以及细胞碎片的毒性大小比较研究，发现藻细胞的毒性作用很强，与藻液相近，细胞内容物也有显著影响，其他组分无显著的毒性作用，结果表明幼鱼摄入PS旨幼鱼致死的原因。较大的幼鱼（12cm）对有毒藻不敏感，暴露在1000cells/mL 10d后，存活率为100％。探讨了塔玛亚历山大藻的致毒机制和途径。

The effect of Dinoflagellate Alexandrium tamarense on juvenile Perch Lateolabrax japonicus

Culture of dinoflagellate Alexandrium tamarense showed obvious impact on the survival of the juvenile Perch(2 5?cm), Lateolabrax japonicus with 96hLC50=4?000 cells/mL. According to the PSP content of the alga,37 48fmol/cell (toxicity equivalent to 11?pg STX eq/cell),the 96hLC50 of the algal toxins was equivalent to 149 92?fmol/L (toxicity equivalent to 44?pg STX eq/L). The toxicity of different fractions of the algal culture (equivalent to 8000?cells/mL):re-suspended cells,cell free medium,cell contents and cell fragments were compared. The re suspended cells showed similar strong impact as the culture on the survival of the juvenile fish, and the cell content also resulted in significant such adverse effect, however, the other fractions did not produce any obvious toxicity. The results indicated that PSP toxins ingestion is the main lethal factor to the juvenile fish mortality. It was also found that the young fish(12?cm)was not sensitive to the toxic alga, which could survive during the exposure to algal cells at 10000?cells/mL for ten days.