Resistance and vulnerability of crustaceans to cytolytic sea anemone toxins.

Crustaceans (Mithraculus, Neopetrolisthes, Periclimenes, Stenorhynchus sp.) living in association with sea anemones, shore crabs (Metopograpsus oceanicus) and brine shrimps (Artemia salina) were found to be resistent to the exposure of cytolytic sea anemone toxins (up to 100 micrograms/ml) and to other membrane-active compounds such as gramicidin A and saponin. The gill filaments of the crustaceans were not affected, indicating that the chitin layer protects the epithelium from the action of the cytolytic toxins. However, crustaceans are highly susceptible to sea anemone toxins when injected parenterally.

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.