Fish species of the genera Amphiprion and Premnas (Perciformes: Pomacentridae) as well
as various crustaceans seek protection from predators among the tentacles of sea anemones,
where they live essentially unharmed from stinging by the host’s nematocysts. The
mucous coats of anemonefish and crustaceans have been suggested as mechanisms that
prevent the discharge of the nematocysts upon contact. Whereas some fish species seem
to produce their own protecting mucous coating, others may acquire mucus from the sea
anemone during an acclimation period, as crustaceans do. Whether the natural or acquired
mucus layers contain components that inhibit nematocyst discharge or simply lack
compounds stimulating the stinging cell’s exocytosis is still unknown.