微小亚历山大藻投喂量与菲律宾蛤仔对麻痹性贝毒累积、转化和排出的动态关系

Dynamic Relationships Between the Feeding Amount of Alexandrium minutum and the Accumulation,Transformation,Elimination of Paralytic Shellfish Poison(PSP)by Ruditapes philippinesis

选用高毒性微小亚历山大藻台湾株和菲律宾蛤仔为研究对象,研究了不同毒藻投喂量对贝类累积和排出麻痹性贝毒(PSP)的影响。实验分为累积和排出2个部分,累积实验设计了4个投喂梯度(A组:2.0×107cell/d、B组:7.0×107cell/d、C组:1.1×108cell/d和D组:2.0×108cell/d),在排出毒素阶段,每实验组又分成投喂无毒饵料藻组和饥饿组并进行比较。结果显示不同投喂梯度组间PSP毒素累积存在明显差异。随着毒藻投喂量的增加,PSP毒性增加,但毒素累积率下降,这说明在一定范围内毒藻投喂量的大小对蛤仔的毒素累积有影响。A组、B组、C组的最高累积量依次为6.5,82.9,113.9μgSTXeq/100g,D组达到本实验的最高累积量154.1μgSTXeq/(100g),但累积率却随着投喂量的增加而递减,分别为1.79%,0.92%,0.42%和0.39%。停止投喂毒藻后蛤仔体内的PSP毒性迅速下降,在排出阶段,对投喂饵料组和饥饿组的比较结果用单因素方差分析(ANOVA)得出P<0.05,结果差异显著,饥饿组的毒性均高于投喂饵料藻组,说明投喂无毒饵料有助于菲律宾蛤仔体内的毒素排出。其中D饵料组和饥饿组间排出速率差异最明显,饵料组的排出速率为13.2μgSTXeq/(100g.d),饥饿组的仅为8.3μgSTXeq/(100g.d),因此将菲律宾蛤仔归属于快速排毒者。

Strongly poisoneous Taiwan strains of Alexandrium minutum, and Ruditapes Philipinarum are used to study the effects of the algal feeding amount on the PSP accumulation and elimination by the shellfish. The experiment consists of 2 steps, i.e. the accumulation step and the elimination step. Furthermore 4 grades of the algal feeding amount are designed in the accumulation step. Two groups, i.e. the group fed with non-poison algae and the group without any feedings are designed in the elimination step to compare the 2 groups. It is shown in the results that the PSP accumulation depends upon the poisoneous algal feed- ing amount. With its feeding amount increase, the PSP toxicity in the shellfish increases while the PSP accumulation rate decreases. The maximum cumulative amounts respectively for Grades A, B, and C are 6. 5, 82.9, and 113.9μgSTXeq/（100g · d）. It becomes 154; 1 μgSTXeq/（100g·d） for Grade D, the grea- test among the 4. However the accumulation rates respectively 1.79%,0.92%,0.42%, and 0.39%. Once the shellfish has not been fed with the poisoneous algae, the PSP toxicity in shellfish becomes rapidly decreased. In the elimination step, the group fed with the non-poison algae is compared with the group fed without any feedings. P〈0.05 as it is shown in the results from the single factor variance analysis （ANO- VA）. It means that there is a significant difference between the toxicities respective of the 2 groups. The group fed without any feedings has stronger toxicity than the non-poison algal feeding group. It is expounded that the non-poison algal feedings are helpful for the shellfish PSP eliminalion. Especially the toxicity difference between the 2 groups becomes the most significant if the group is fed with the Grade D of the non-poison algal amount. The group fed with Grade D of the non-poison algal feeding has an elimination rate of 13.2 μgSTXeq/（100g·d） and the other group has a rate of 8.3 μgSTXeq/（100g·d）. Therefore the shellfish belongs to the rapid detoxification species.