Paralytic shellfish toxin amount and toxic components by site in ark shell and Japanese cockle caught in Osaka Bay, eastern Seto Inland Sea, Japan

Abstract

　Ark shell and Japanese cockle collected in 2014 and 2015 were dissected into four parts (muscle, mantle/adductor, gill, and viscera) and paralytic shellfish toxins contained in each part were analyzed. In ark shell, paralytic shellfish toxins were distributed in all four parts and were abundant in the muscle, mantle/adductor and viscera. In Japanese cockle, the toxins were abundant in the gill and viscera, and very low in the muscle. The percentage of toxic components was high in GTX2 and GTX3 in both species. In ark shell, STX tended to be high in the early stage of poisoning as well, except in the viscera. STX in Japanese cockle was high only in the gill. These results suggest that in ark shell, the toxic components diffuse from the viscera to the whole body shortly after causative toxic algae appeared, whereas in Japanese cockle, the toxic components migrate only to the gills where they are converted to STX.