Aquarium Studies on the Ability of Potential Predators to Learn to Avoid Humbug Damselfish, Dascyllus aruanus (Pisces, Pomacentridae) as Prey

Five species of potential predators of D. aruanus were trained in aquaria using a simple reward versus no‐reward training technique in which D. aruanus (no‐reward) and a variety of alternative prey species (reward) were presented simultaneously to the former. All the predators tested exhibited an ability to learn to approach the reward species of fish in preference to D. aruanus . Results are discussed in relation to the recently proposed theory that potential predators may learn in the field not to attack D. aruanus but to concentrate on alternative and more easily caught prey.