Gambierdiscus toxicus is an armoured, marine, benthic dinoflagellate species. It is anterio-posteriorly compressed with epitheca and hypotheca?s very similar in size. The theca is very thick covered with numerous deep and dense pores. This species is autotrophic creating energy via several golden-brown chloroplasts. The crescent-shaped nucleus is oriented ventrally (Adachi & Fukuyo, 1979).