有害赤潮生物球形棕囊藻对卤虫的毒性研究

利用1997年10月和1998年6月分别在广东汕头饶平海域和香港海域分离到的球形棕囊藻,即球形棕囊藻香港株(Phaeocystis globosastrain HK)和球形棕囊藻汕头株(Phaeocystis globosastrain ST),在实验室条件下研究其对四日龄卤虫(Artemia sinica)的急性毒性。结果表明,对数生长期的HK株藻液24h对卤虫LC₅₀约为2.9×10⁵cell·mL^-1。对数期的ST株对卤虫的毒性难以达到半致死浓度,衰亡期的ST株24h对卤虫LC₅₀约为9.89×10⁶cell·mL^-1。在上述浓度下两者半致死时间分别为20.91h和26.62h,而对数生长期的HK株和衰亡期的ST株的培养物过滤液24h对卤虫LC₅₀则分别为7.1×10⁵cell·mL^-1和1.457×10⁷cell·mL^-1,且在该浓度下的半致死时间分别为26.56h和28.02h。实验表明,HK株藻液和滤液的毒性均大于ST株,且藻液的毒性均大于滤液。

Studies on the toxicity of tow strains Phaeocystis globosa scherffeto to Artemia sinica

The acute toxicities of tow strains of Phaeocystis globosa scherffel isolated respectively from the coastal waters of Hong Kong (HK) in June 1998 and Shantou (ST) of Guangdong Province in October 1997 were studied under laboratory conditions. The results showed that two strains were pernicious to Artemia sinica. 1) Media Lethal concentration (MLC) for HK strain of logarithmic phase was 2.9×10⁵ cell·mL^-1.Median Lethal Time (MLT) was 20.91 hours. 2) MLC was 9.89×10⁶ cell·mL^-1 for ST strain of decline phase, and MLT was 26.62 hours. 3) The cell-free liquids of tow stains of Phaeocystis globosa scherffel were also pernicious to Artemia sinica, but the adverse effect of them were not so remarkable as whole cells culture medias. MLT was 26.56 hours for cell-free liquids of HK strain, and 28.02 hours for ST strain. MLC for them respectively were 7.1×10⁵ cell·mL^-1 and 1.457×10⁷ cell·mL^-1.The experimental results showed that the toxicities of cell and cell-free liquids of HK strain were more remarkable than ST strain, and the toxicities of cell liquids were more acute than cell-free liquids.