Abstract:The advances made in studies of pectenotoxins (PTXs), including the chemical structures, source organisms, toxicities, geological distribution, occurrence and metabolism in marine organisms, and risks associated with PTX-contaminated seafood, were reviewed. PTXs, are a group of cyclic polyether-lactone toxins first detected in the cultured Japanese scallop Patinopecten yessoensis in 1984. Up to now, around 20 different PTXs have been identified from algae and shellfish samples. Some PTX toxins, like PTX-2, are mainly found in algae, and other PTX toxins are supposed to be their metabolites in shellfish or artifacts produced during the sample preparation process. PTXs are mainly produced by toxic dinoflagellates in Genus Dinophysis, including D. acuta, D. fortii, D. acuminata, D. caudata, D. norvegica, D. rotundata, D. infundibulus and D. sacculus. PTX-2 is the major toxin produced by the toxic Dinophysis spp.. Recently, PTX-1, PTX-11 and PTX-12 also have been detected in phytoplankton samples containing Dinophysis cells. Filter-feeding shellfish could accumulate PTXs produced by toxic Dinophysis, and PTXs have been widely detected in mussels, scallops and clams collected from countries in Asia, Europe, Australia and America. Metabolism and depuration of PTXs in shellfish depend upon the shellfish species. In the greenshell mussel Perna canaliculus collected from New Zealand, PTX-2 produced by D. acuta is mainly transformed into PTX-2 seco acid (PTX-2sa) and 7-epi-PTX-2 seco acid (7-epi-PTX-2sa). But in the Japanese scallop Patinopecten yessoensis, PTX2 would be oxidized into PTX-1, PTX-3 and PTX-6. PTXs have a low diarrhoeic potential, but show high haptotoxic effects in mice. The LD50 value of PTX-2 determined by the mice intraperitoneal injection method is 219μg/kg. Despite the high intraperitoneal injection toxicity, the oral toxicity of PTX toxins is relatively low. The LD50 value of PTX-2 determined by the oral administration method in mice is over 5000μg/kg. To protect seafood consumers, regulation for PTXs in shellfish products have been proposed and adopted by many countries. The European Community Reference Laboratory suggested that PTX-2 content in edible portion of shellfish should be no more than 16μg/100g wet weight. Generally, shellfish contaminated by PTXs was considered low risk due to the relatively low oral toxicity and the transformation of PTX toxins in shellfish, which would significantly decrease their toxicity. In China, 16 species of Dinophysis, including 5 toxic species, have been identified along the coast of China based on the results of phytoplankton investigation. And some toxic species, like D. fortii in the Bohai Sea and D. caudata in the South China Sea, have formed algal blooms. However, works on PTXs and other lipophilic phycotoxins are still limited in China. So far there is little knowledge on PTX toxins produced by Dinophysis spp., but PTX1 has been detected in shellfish samples. Based on the review, further studies on phycotoxins in China are suggested, including preparation of toxin standards, toxicity and toxicological studies of new phycotoxins, and ecological studies of Dinophysis blooms, to protect the health of seafood consumers.