Gambierdiscus polynesiensis is a species of toxic (ciguatoxin- and maitotoxin-like toxicity) dinoflagellate. It is 68âÂÂ85 üm long and 64âÂÂ75 üm wide dorsoventrally and its surface is smooth. It is identified by a large triangular apical pore plate, a narrow fish-hook opening surrounded by 38 round pores, and a large, broad posterior intercalary plate. Its first plate occupies 60% of the width of the hypotheca.