Dead bleached coral provides new surfaces for dinoflagellates implicated in ciguatera fish poisonings

Synopsis

Dead sections of bleached corals in the United States Virgin Islands and British Virgin Islands were found to be colonized by filamentous algae harboring epiphytic dinoflagellates implicated in ciguatera fish poisonings. The dinoflagellates Ostreopsis lenticularis, Prorocentrum concavum, and P. lima were found in association with filamentous algae growing on dead sections of bleached Montastrea annularis and Acropora cervicornis. Several fish species from the families Acanthuridae, Pomacentridae, and Scaridae were observed to readily consume this filamentous algae/epiphytic dinoflagellate food source. Such fishes are common prey for large piscivores inhabiting tropical reefs. An increased incidence of ciguatoxic fishes may occur on reefs where bleaching events have caused significant coral mortality.