The role of chemical alarm cues in risk assessment and predator recognition in coral reef fishes

摘要: Through the removal of individuals, predation shapes distribution and abundance prey communities. Consequently, how species detect respond to threats within their environment will determine survival future fitness. The mere presence predators in an has a significant effect on life histories individuals. use visual, olfactory auditory cues allows learn about associated risks way that development predator specific antipredator responses. In complex environments, such as coral reefs, are thought be especially important increased complexity reduces access visual cues. There is evidence suggest chemical alarm maybe used by wide range reef fishes, however there lack information regarding role play risk perception recognition. This study therefore investigates fishes assess recognise they represent. To understand risk, need what able detect. How juvenile reefs from heterospecific guild members unclear but should enhance assessment. Chapter 2 tested if naive fish have innate recognition whether arises phylogenetic conservation Naive Amphiprion percula were see displayed responses four closely related (family Pomacentridae), distantly sympatric (Asterropteryx semipunctatus; family Gobidae) saltwater control. Juveniles reductions foraging rate when exposed all confamilial intensity response was strongly correlated extent which A. percula. These findings demonstrate conserved Pomacentridae family, predicted relatedness hypothesis. In absence must learnt efficient manner, particularly entering novel environment. Predation pressure selectively promote mechanisms enable rapid identification predators. 3 ability marine fish, lemon damselfish (Pomacentrus moluccensis), simultaneously identity multiple previously unknown Individuals conditioned with „cocktail‟ odours (from two non-predators) paired either conspecific cue or control then following day for individually (one one non-predator). ‘cocktail’ responded individual not controls. results process sources identities still individually. rapidly assimilate significantly assessment chances survival. Learnt recognition, although potentially costly, provides animals adaptive mechanism adjust current levels risk. Prey may reduce costs learning can learned known unfamiliar. 4 demonstrated that, community where predict predatory status low (i.e. high diversity non-predators), generalise congeneric species. P. moluccensis, odour moon wrasse, Thalassoma lunare, risky stimulus subsequently only T. lunare odour, also amblycephalum hardwicke odours. Recognition extended beyond genus level. Our showed moluccensis could distinguish between non-predators generalising appear depend accurately based knowledge functional previous generations been exposed. In communities biodiversity, crucial success. Coral enter new environments apparently both non-predators. remarkable efficiency using means mistakes occur inadvertently it not. Latent inhibition pre-exposed negative reinforcement animal likely threat. 5 common recognize non-threatening through latent inhibition. Furthermore, we override conditioning numerous times. highlight correct continually updating threat posed other vicinity. Fishes different suits throughout ontogeny most relevant situation. 6 spiny chromis, Acanthochromis polyacanthus, originating conspecifics ontogenetic stages origin affected its efficacy after being juveniles failed larger demonstrates highly selective conspecifics, responding those developmental stage.