Knowing Your Behaviour: The importance of Behavioural Assays in the Characterisation of Chemical Alarm Cues in Fishes and Amphibians

Abstract

Predation provides a strong selective pressure that shapes theantipredator responses of aquatic animals. This has led to the evolutionof chemical alarm systems where chemicals released from injured preyevoke antipredator responses that enhance survival when encounteringpredators. The chemical structure of alarm cues is unknown and littlework has been conducted on characterising/identifying them. In thisstudy, we use high performance liquid chromatography to separate skinextracts from fathead minnows (Pimephales promelas) and larval grey treefrogs (Hyla vesicolor) and then deliver the fractions back to testanimals to determine which portions of the skin extract leads toantipredator behaviour. In fathead minnows, one fraction of the skinextract evokes antipredator behaviour, but in grey tree frog tadpoles nosingle fraction of the extract caused antipredator behaviour. Theseresults provide insight into the characterisation of chemical alarm cuesand the importance of behavioural assays in this process.