A cleaner wrasse performs its service on a whitebar surgeonfish. Cleaner wrasse establish stations where other fish can visit to be cleaned of mucus and parasites.

When I’m snorkeling, I enjoy visiting these stations to see what’s going on and which fish are availing themselves of the services offered. Some of these fish are predators who, in other circumstances, might be expected to make a meal of a cleaner wrasse. But because of the beneficial service they offer, cleaner wrasse get a free pass with predators.