Abstract

Chemosensory cues, including disturbance cues, are important indicators of predation risk in aquatic systems. To date, little is known about disturbance cues although they are thought to exist in a variety of fishes and are believed to indicate lower risk as compared to damage-released alarm cues. Previous studies suggest disturbance cues are composed of a metabolic waste product, likely ammonium, though this has not been directly tested in fish. For my thesis, I wanted to verify the presence of and characterize the response to disturbance cues in two taxonomically distant species: juvenile convict cichlids ( Archocentrus nigrofasciatus ) and juvenile rainbow trout ( Oncorhynchus mykiss ). I also wanted to test the assumption that the disturbance cue is a metabolic waste product, specifically ammonium. Both species responded to the disturbance cue in a threat-sensitive manner, which was expected given the low risk nature of the cue. As well, my results suggest ammonium is not likely the major component of the disturbance cue although it may be some type of metabolic waste product. Future work is needed in order to determine the in major constituent of the disturbance cue and to further examine its ecological importance.