Distribution and sequestration of palytoxin in coral reef animals.

In the reefs off the Colombian coast (Caribbean Sea) and around Lizard Island, Australia (Pacific), palytoxin (PTX), which has been detected in zoanthid species of the genus Palythoa, also occurred in various other marine organisms living in close association with zoanthid colonies, e.g. sponges (Porifera), soft corals (Alcyonaria), gorgonians (Gorgonaria), mussels, and crustaceans. Predators, e.g. polychaete worms (Hermodice carunculata), a starfish (Acanthaster planci) and fish (Chaetodon species) feeding on Palythoa colonies, accumulate high toxin concentrations in their organs, where PTX is stored in its active form. The high level of toxin tolerance observed in marine animals may enable the wide distribution of PTX in marine biota and its transport and sequestration in food chains.

Studies on the origin and distribution of palytoxin in a Caribbean coral reef.

In coral reefs of the Caribbean Sea (Colombia) palytoxin (PTX) has been detected in zoanthid species of the genera Palythoa and Zoanthus by assaying the delayed haemolysis in human erythrocytes produced by aqueous extracts, which is inhibited by ouabain pretreatment, and by HPLC. The toxin content of the polyps and colonies is highly variable and is not correlated with their reproductive cycle or with the amount of symbiotic algae. Sequestration of PTX has been observed in crustaceans (Platypodiella sp.) living in close association with Palythoa colonies and in polychaete worms (Hermodice carunculata) feeding on the zoanthids. Resistance of marine animals to the toxin may enable it to enter food chains.