塔玛亚历山大藻毒素及其对中国对虾的急性毒性

利用美国分析化学家协会(Association of Official Analytical Chemists, AOAC)所推荐的小鼠生物法(mouse bioassay, MBA), 测定了塔玛亚历山大藻(Alexandrium tamarense)(ATHK藻株)毒素粗提液的麻痹性贝毒(paralytic shellfish poisoning, PSP)毒性;采用浸浴方式, 研究了该藻株对中国对虾的急性毒性; 采用HE染色方法, 分别对有毒藻浸浴处理和毒素粗提液注射处理后96 h中国对虾(Fenneropenaeus chinensis)的鳃和肝胰腺石蜡切片进行观察。结果表明, 该藻株麻痹性贝毒毒性为3.9×10^–5 MU/cell (相当于7.3 pg STX Equal/cell), 在同种藻株中属低毒藻株; 在96 h急性毒性实验中, 塔玛亚历山大藻对中国对虾的半致死浓度(LC₅₀)为1.0×10⁴ cells/mL, 安全浓度(SC)为1.0×10³ cells/mL; 石蜡切片观察发现, 塔玛亚历山大藻与毒素粗提液分别引起了鳃和肝胰腺组织出现细胞肿胀、空泡化等病理变化。以上研究结果提示, 塔玛亚历山大藻对中国对虾有急性致死作用。为了保证中国对虾的健康养殖, 养殖水体中的塔玛亚历山大藻浓度至少应该控制在1.0×10³ cells/mL以下; 鳃的病变直接导致对虾窒息死亡可能是塔玛亚历山大藻暴露后对虾急性致死作用的最重要原因;塔玛亚历山大藻所产的PSP毒素可引起虾体代谢和解毒的主要器官—肝胰腺的病变。

The toxicity of Alexandrium tamarense to Fenneropenaeus chinensis

Cultured shrimps are often exposed to different toxearing practices that may affect survival and quality of the product.Alexandrium tamarense, a dinoflagellate producing paralytic shellfish poison, on Chinese shrimp, A mouse bioassay (MBA) method was used to determine the toxicity of the extract from A. tamarense on studied. In addition, histopathology observation was conducted in gill and hepatopancreas after 96 h exposure to 1.0×10⁴ cells·mL⁻¹ and intramuscular injection with 20 µL the extract from was low, which was 3.950 of was , the safe concentrations were obtained, which was and the extract could cause some abnormal histological changes in gill and hepatopancreas, respectively, such as cellular swelling and vacuolated. Our study revealed that . Accordingly, the concentration of in the prawn ponds should be controlled below cells/mL at leastexposure. The lesions in the gills of that impedes the occurrence of gaseous interchanges isthemostlikelycauseofshrimp death after could cause thelesions in the hepatopancreas of