Predator inspection behaviour and attack cone avoidance in a characin fish: the effects of predator diet and prey experience

Abstract

Individuals that dare approach predators (predator inspection behaviour) can reduce their overall risk of predation by engaging in attack cone avoidance. Under laboratory conditions, we investigated the interaction between predator diet and prey experience with predators in attack cone avoidance during predator inspection visits by glowlight tetras,Hemigrammus erythrozonus (Characidae, Ostariophysi). Shoals of predator-experienced versus predator-naı̈ve glowlight tetras were exposed to live Jack Dempsey cichlids, Cichlasoma octofaciatum, that had been fed a diet of tetras (possessing an alarm pheromone) or swordtails, Xiphophorus helleri (lacking a recognizable alarm pheromone). Naı̈ve tetras exposed to tetra-fed predators significantly increased their antipredator response (increased shoaling, dashing and freezing) and altered their predator inspection behaviour (increased latency to respond, decreased rate of inspection and decreased inspecting group size) compared with naı̈ve tetras exposed to swordtail-fed predators. In addition, naı̈ve tetras exposed to tetra-fed predators directed significantly greater proportions of their inspection visits towards the tail versus the head of the predator (attack cone avoidance) versus naı̈ve tetras exposed to swordtail-fed predators. Experienced tetras, regardless of predator diet, also significantly increased antipredator responses and altered their inspection behaviour. Experienced tetras also displayed significant attack cone avoidance. These data suggest that both predator diet and prey experience play a significant role in the threat-sensitive mediation of predator inspection behaviour in prey fish. Copyright 2002 The Association for the Study of Animal Behaviour. Published by Elsevier Science Ltd. All rights reserved.