枝角类为媒介的麻痹性贝类毒素传递与代谢研究

Study on transfer and metabolism of paralytic shellfish poison in cladoceran Moina mongolica

为了弄清麻痹性贝类毒素(paralytic shellfish poisoning,PSP)在海洋生态系统中的产生、转化和归宿,本文以海洋枝角类为媒介,研究了麻痹性贝类毒素在海洋食物链中的传递与代谢过程。结果表明,PSP毒素可以沿甲藻塔玛亚历山大藻(Alexandrium tamarense)→枝角类蒙古裸腹溞(Moina mongolica)→红鳍东方鲀(Fugu rubripes)鱼苗进行传递和代谢。整个实验过程中,塔玛亚历山大藻、蒙古裸腹溞、红鳍东方鲀均检测到C1+2,鱼苗体内还发现似新生成的neoSTX。毒素传递过程中,C1+2中低毒性的α型毒素C1比例增大;毒素在鱼苗体内净化时,各PSP成分和总毒素含量普遍随净化时间的延长而减少。该结果为解释麻痹性贝类毒素为何在海洋各营养级生物体中广泛存在提供了直接的证据,也为我国开展麻痹性贝类毒素的监测和管理提供了新的理论依据。

In order to clarify the formation, transformation and end-result of paralytic shellfish poison （PSP） in marine ecosystem, the transfer and metabolism of PSP introducing cladoceran Moina mongolica as a biological vector were studied. The results showed that transmission and conversion of PSP toxins happened when larval fish of Fugu rubripes preyed on cladoceran Moina mongolica that has ingested the toxic dinoflagellate Alexandrium tamarense. All of them contained C1＋2 toxins, while Fugu rubripes may create new neoSTX toxin. The ratio of α toxin （ C1 ） to β toxin （ C2 ） increased when PSP toxins were transferred along the food chain, while all elements and the total content of PSP toxins almost reduced remarkably in the larval fish of Fugu rubripes with the prolong of depuration. The result would provide a direct proof of PSP toxins＇wide existence in the different nutrient level organisms in the marine ecosystem, and act as a new theory basis for their monitor and management.