Nuclear-follower foraging associations of reef fishes and other animals at an oceanic archipelago

Synopsis Fish species in many families and different trophic levels forage by following fishes and other animals. This interspecific foraging association was examined at an oceanic archipelago in the tropical West Atlantic. We recorded 27 reef fish species, two invertebrate species, and one turtle species playing the nuclear role, and 26 reef fish species acting as followers. The puddingwife wrasse following the spotted goatfish was the commonest foraging association recorded. The spotted goatfish was the nuclear fish that attracted the largest number of follower species (68% of the total number of follower species). The coney and the Noronha wrasse were the follower species that associated with the largest number of nuclear species (63 and 55% of the total number). About 20% of the reef fish species recorded in the archipelago engages in interspecific foraging associations. Substratum disturbance is a strong predictor for a fish displaying the nuclear role in the association, whereas the follower role may be predicted by carnivory. Nuclear species are diverse both in morphology and behaviour, and the nuclear role may be played either by fishes or other marine animals from invertebrates to turtles. Followers, on the other hand, comprise fishes only, which tend to display a more uniform feeding behaviour.