ABSTRACT

Saxitoxin and its analogues (STXs) are potent neurotoxins that block voltage-gated sodium channels on excitable cells (1). These toxins are produced by several species of dinoflagellates such as Alexandrium tamarense and A. catenella (2). During a bloom of these species, filter-feeding bivalves become toxic by ingesting them. Human consumption of toxic shellfish results in severe food poisoning known as paralytic shellfish poisoning (PSP) owing to its main symptom, paralysis. Shellfish farming areas infested by these species run costly monitoring programs to check for the causative dinoflagellates in the water. When these are present, regular tests for toxins in associated seafood products such as bivalves are carried out and often result in the prohibition of harvesting of these products. Thus, the contamination of bivalves with STXs has posed severe problems for the shellfish culture industry as well as for public health.