Palytoxin in the marine food web

Abstract

Palytoxin is produced by (or in) zoanthids (Hexacorallia) of the genus Palythoa and Zoanthus. It causes a broad range of in vivo and in vitro effects through the Na super(+)/K super(+)-ATPase of cell membranes by inducing channel or pore formation, particularly in terrestrial (experimental) animals such as mice and rats. Palytoxin is easily assayed by delayed haemolysis of human erythrocytes, which is potentiated by borate and inhibited by ouabain. It can also be identified by high-performance liquid chromatography. In the reefs of the Caribbean Sea several fish species (Chaetodon, Stegastes sp.) predate zoantharian colonies and crustaceans, which live in close association with these colonies. They accumulate palytoxin in their body, e.g. in skin, muscle, gills, liver, intestines and ovaries. The puffer fish, Sphoeroides sprengleri, also contains remarkable palytoxin concentrations in the skin and liver, as well as tetrodotoxin. This indicates that palytoxin is easily sequestered, even by vertebrates, and may enter the marine food chain