During fieldwork at the Abrolhos reefs (north-east Brazil) the whitespotted filefish Cantherhines macrocerus was observed predating a reproductive colony of the zoanthid Palythoa caribaeorum. Several fresh bite marks observed in the colonies suggest that other individuals and probably other species were also feeding on the zoanthid. This is the first record of predation on this zoanthid during its reproductive stage. Since P. caribaeorum contains anti-predation chemical defences, we discuss that the presence of egg-bearing polyps might increase the predator benefit in the predation trade-off, i.e. it might be more worthwhile to deal with such defences when the energy budget of eggs is also involved. Therefore, the reproductive stage of chemically defended organisms might shape the frequency and intensity of such interaction.