Gambierdiscus toxicus in gut content of the surgeonfish Ctenochaetus strigosus (herbivore) and its relationship to toxicity.

Flesh of surgeonfish, Ctenochaetus strigosus, obtained from corresponding catches of C. strigosus implicated in ciguatera poisoning outbreaks was examined for ciguatoxin and related polyethers by the stick test enzyme immunoassay. Simultaneously, gut contents of the fish were examined under phase microscopy for the presence of Gambierdiscus toxicus. Eighty-seven per cent of the fish were stick EIA positive, while 98% were positive for G. toxicus in gut contents. The data obtained suggest a relationship between G. toxicus in gut content and tissue toxicity levels. This is in agreement with previous studies which demonstrated a relationship between G. toxicus in fish gut content and toxicity of the flesh to animals and humans.