剧毒卡尔藻对海洋生物毒性及机制的初步研究

A preliminary study of the toxicity and mechanism of Karlodinium veneficum to Marine Organisms

剧毒卡尔藻(Karlodinium veneficum)是一种有毒甲藻,近年在我国沿海已经爆发过藻华,值得关注。本文研究了剧毒卡尔藻对不同粒径、不同营养级的几种海洋生物褶皱臂尾轮虫(Brachionus plicatilis)、卤虫(Artemia salina)、黑褐新糠虾(Neomysis awatschensis)、中华哲水蚤(Calanus sinicus)存活及摄食的影响。研究发现:该藻对轮虫、卤虫存活影响较大,对黑褐新糠虾存活的影响较小,对中华哲水蚤存活几乎无影响。48 h,对轮虫的半数致死密度LC50≈3400 cells/m L;96 h对卤虫的半数致死密度为LC50≈4800 cells/m L;对黑褐新糠虾的半数致死密度为LC50≈89000 cells/m L;在89000 cells/m L的藻密度下,中华哲水蚤存活率约为80%。该藻不同组分对实验生物的影响是不同的,细胞破碎液对轮虫、黑褐新糠虾的影响最大;细胞外液对卤虫的影响最大。该藻对生物的摄食影响则发现,24 h内,轮虫、卤虫、中华哲水蚤均摄食该藻,且3种生物的摄食率随着藻密度增高而增加。可见,剧毒卡尔藻对不同生物的影响不同,其现场藻密度一般可达到104cells/m L,对轮虫、卤虫存活影响很大;该藻对生物有不同的致毒机制和致毒途径。结果表明:该藻藻华爆发,可能会对浮游生态系统产生较大影响;研究有害藻对不同粒径、不同营养级生物的影响,才可以更全面的反映出它对生态系统的危害。

Karlodinium veneficum is a kind of toxic dinoflagellate and has broken out in China in recent years. This paper studied the effects of Karlodinium veneficum to Brachionus plicatilis , Anemia salina, Neomysis awatschensis and Calanus sinicus which belong to different sizes and trophic levels. We found that it has greater effects to Brachionus plicatilis and Anemia salina than Neomysis awatschensis ,and it almost has no effects to Calanus sinicus. The LC50 （medium lethal con- centration） of Brachionus plicatilis is about 3400 ceils / mL in 48 h. The LC50 of Artemia salina is about 4800 cells / mL in 96 h. The LC50of Neomysis awatschensis is about 89000 cells / mL in 96 h and the survival rate of Calanus sinicus is about 80% under the circumstances. The effects of different fractions of Karlodinium veneficum are different on experi- mental organisms. The cell lysate has greatest effects on Brachionus plicatilis and Neomysis awatschensis. The extracellu-lar fluid has greatest effects on Artemia salina . The Brachionus plicatilis, Artemia salina,and Calanus sinicus ingest Kar- lodinium veneficum and as the density increased, the feeding rate increase in 24 h. So we can concluded that Karlodinium veneficum has different effects to marine organisms and different toxic mechanisms and pathways. When the algal density is 104cells/mL（ the algal blooms have existed）,the Brachionus plicatilis and Anemia salina have been greatly influ- enced. It may has greater effects to Plankton ecosystem if algal blooms break outand can know the hazard more compre- hensive by studying the effects of harmful algal to different sizes and trophic levels organisms.