In coral reefs of the Caribbean Sea (Colombia) palytoxin (PTX) has bee
n detected in zoanthid species of the genera Palythoa and Zoanthus by
assaying the delayed haemolysis in human erythrocytes produced by aque
ous extracts, which is inhibited by ouabain pretreatment, and by HPLC.
The toxin content of the polyps and colonies is highly variable and i
s not correlated with their reproductive cycle or with the amount of s
ymbiotic 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 zoanth
ids. Resistance of marine animals to the toxin may enable it to enter
food chains.