ciguatoxin

noun

ci·​gua·​tox·​in ˈsē-gwə-ˌtäk-sən  ˈsig-wə- 

: a potent heat-stable neurotoxin that is produced by a marine dinoflagellate (Gambierdiscus toxicus) and causes ciguatera poisoning in those who eat fish (as barracuda or amberjack) in which toxic levels of it have become concentrated

also : any of several related neurotoxins causing ciguatera