Schooling barracuda

Photo: Sylvain Le Bris · CC BY-NC

Chevron barracuda form enormous spiralling schools above Dolphin Reef North's plateau, sometimes numbering in the thousands and creating a living tornado of silver that blocks sunlight from below. They school as juveniles and sub-adults for predator protection, with the rotating formation confusing predators attempting to isolate individual fish. The schools disperse at night when adults become solitary ambush hunters, making the daytime massing aggregation a purely defensive collective behaviour.