Takumi Iijima, a third-year doctoral student in the United Graduate School of Agricultural Sciences (affiliated with Kochi University), received the Outstanding Poster Presentation Award (Doctoral Student Division) at the 2026 Spring Meeting of the Japanese Society of Fisheries Science, held from March 26 to March 29, 2026.
This study focused on the accumulation in bivalves of tetrodotoxin (TTX), a potent neurotoxin known as pufferfish toxin, with the aim of elucidating the factors responsible for this toxification phenomenon. In recent years, TTX has been detected in bivalves such as scallops, raising concerns about its association with toxification. However, the organisms responsible for this phenomenon have not yet been fully identified.
Under the supervision of Professor Masao Adachi of Kochi University, Takumi conducted a study on scallops from Hokkaido using metabarcoding analysis of plankton DNA present in the digestive tracts of bivalves. As a result, he revealed that the feeding rate of specific plankton species in their diet increased during periods of toxification. Future studies are expected to lead to the identification of the organisms responsible for scallop toxification by isolating and cultivating these plankton and verifying their ability to retain and produce TTX.
Award-winning Presentation
「北海道産ホタテガイのフグ毒による毒化状況ならびに餌生物の網羅的解析」
“Comprehensive analysis of pufferfish toxin contamination and food organisms in scallops from Hokkaido”
＜The United Graduate School of Agricultural Sciences＞