Of all the things an animal could eat, corals are arguably one of the toughest, thanks to their thin, mucus-covered flesh packed with venomous stinging cells spread over a razor-sharp skeleton. Perhaps that explains why of the more than 6,000 fish species that live on the reef, only 128 are known to feed on corals. Now, researchers reporting in Current Biology on June 5 have discovered how at least one species of coral-feeding fish does it. They “kiss” the flesh and mucus off the coral skeleton using protective, self-lubricating lips.