Bigeye trevally (fish) -> Cardinalfish (prey fish)
Like lions on the prowl, bigeye trevallies (Caranx sexfasciatus) form hunting schools to patrol the reef for dense schools of prey fish, like cardinalfish. Voracious predators, bigeye trevallies have evolved lightning swiftness and exceptional cooperation that allows them to surround prey schools, herding them in close to the reef. The prey panic, and their tightly organized schools turn to chaos, giving the trevallies a chance to attack.
Enormous schools of prey fish (many species, including cardinalfish (Cheilodipterus parazonatus)) glide across the reef in search of tiny zooplankton. The prey fish, in turn, are eaten by many species of larger fish, like bigeye trevallies. Schooling offers some protection from predators, since each fish can be on the lookout, but it requires precise choreography to work well. Schooling fish have evolved special vibration sensors along their lateral sides that allow them to literally feel each other's movements and stay in synch.