Gambierdiscus toxicus is a species of photosynthetic unicellular eukaryote belonging to the Alveolata, part of the SAR supergroup.

It is a dinoflagellate which can cause the foodborne illness ciguatera,[1] and is known to produce several natural polyethers including ciguatoxin, maitotoxin, gambieric acid, and gambierol.

[6] It is often found at the surface of various macroalgae, dead coral, sand and in water column[7] suggesting that the certain chemical compounds in algal exudates may play an important role in the process of attachment .

[8] This algae species is capable of producing a variety of bioactive polyketide natural products such as ciguatoxin with characteristic fused-ring cyclic polyether structure.

It is believed that the biosynthesis pathway involves epoxide as an intermediate which then undergoes a cyclization reaction to form the fused-ring cyclic polyether structure.