The little blue-yellow fish (a Spanish Hogfish) in the picture on the right looks like it doesn't have long to live, doesn't it?
But nothing's farther from the truth. This fish is hard at work. The fish surrounding it (called Grunts, apparently) are inviting, or rather begging, the Spanish Hogfish to clean them. This is happening at a so called 'Cleaning station'. A cleaning station is where fish go when they need a good scrubbing. Kind of a car-wash for fish, where they'll get cleaned of bacteria, dead skin and parasites. Even fish that are normally enemies of the cleaning fish go to the cleaning stations to get themselves cleaned by their, otherwise, enemies.
These cleaning stations are beneficial for both the cleaner and the fish being cleaned. One gets parasites and other stuff cleaned and the other gets free food and some rest at the 'neutral zone'.
Apparently, they even provide services to humans.