一株非PSP产毒的亚历山大藻对黑褐新糠虾的急性和慢性毒性影响

The acute and chronic effects of a non-PSP producer,Alexandrium affine on Neomysis awatschensis

报道了一株非PSP产毒的相关亚历山大藻(Alexandrium affine,株AC-1)对甲壳类生物黑褐新糠虾(Neomysis awatschensis)的存活、生长及种群繁殖的研究结果。通过研究发现,该藻对黑褐新糠虾有急性致死作用,96 h LC50为5 000 cells.mL-1。研究该藻各组分:藻液、藻细胞重悬液、藻细胞培养过滤液、内容物对糠虾存活的影响时,发现只有藻液和藻细胞重悬液显著降低了糠虾存活率,过滤液和内容物也有影响,但不显著,表明相关亚历山大藻活体藻细胞的毒性最强。通过对糠虾63 d的慢性毒性实验研究,发现在密度为50 cells.mL-1藻液中,糠虾的繁殖就受到了不利影响。试验进行到63 d结束时,糠虾日最高产虾数、总产幼虾数、总产虾天数都明显减少,初次产虾时间推迟,繁殖中断增加。且该藻对黑褐新糠虾亲虾的存活、生长也有一定的影响,糠虾亲虾的存活率为对照的71%,而体长和体重分别为对照组的87.3%和97.8%,但差异尚不显著(P>0.05)。可见,相关亚历山大藻(AC-1)虽然不产生PSP毒素,但也能对甲壳类生物的种群数量和资源补充产生不利影响。

In this paper, the effects of ,.iexandrium affine on the survival, growth and reproduction of Mysid Neomysis awatschensis were studied. The results showed that A. a3fine had an acute lethal effect on N. awatschensis and the 96 h LC50 was about 5 000 cells·mL^-1. The toxicity comparison of different fractions （Algal culture, re-suspended cells, free-cell medium, and cell content） showed that the algal culture and resuspended algal cells had the remarkable adverse effect on the survival of N. awatschensis, while the free-cell medium and cell content also had the adverse impact, although not significant, indicating that the toxicity of A. affine was mostly related with the living algal cells. Chronic experiment （63 days） showed that the reproduction of N. awatschensis was obviously affected at 50 cells·mL^-1 A. affine. At the end of the experiment, the highest number of juveniles per day, the total numbers of juveniles produced and the total releasing days were reduced, and the first releasing time was delayed, as well as reproduction break of the parent mysids were increased, when exposed to the algae. It was also found that A. affine could affect the survival and growth of the parent mysid： in 50 cells·mL^-1A. affine, the survival rate of N. awatschensis was 71%. The length and weight of adult shrirnps were 87.3 % and 97.8 %, respectively, but the difference was not significant （P〉0.05）. Therefore, A. affine could have adverse influence on population and resources of crustacean.