PARENT SESSION
Poster Session 29: Predator / Prey Ecology
Thursday, August 11, 5:00 PM - 6:30 PM, Exhibit Hall 220 A-E, Level 2, Palais des congrès de Montréal
Field examiniation of acquired predator recognition by juvenile Atlantic salmon under neutral vs. acidic conditions.
Roh, Ellie*,1, Leduc, Antoine1, Breau, Cindy2, Brown, Grant1, 1 Concordia University, Montreal, Quebec, Canada2 University of New Brunswick, Frederickton, New Brunswick, Canada
ABSTRACT- Salmonids are known to acquire the recognition of novel predator cues when they are paired with conspecific chemical alarm cues. Such acquired predator recognition is leads to increased survival during encounters with live predators. However, the ability to detect these critically important chemical alarm cues under weakly acidic conditions, resulting primarily from anthropogenic acidification, is impaired. We conducted the current study to determine if: 1) wild juvenile Atlantic salmon (Salmo salar) can acquire the recognition of a novel cue, and 2) if chemosensory mediated learning is impaired under weakly acidic conditions. Tagged juvenile Atlantic salmon in neutral (mean pH 7.12) and acidic (mean pH 6.08) streams were exposed to conspecific alarm cue paired with a novel odour (lemon extract), or a stream water and novel odour control. Twenty-four hours later, we exposed all fish to lemon extract alone and observed their antipredator behaviour. In neutral streams, fish conditioned to the alarm cue and novel odour exhibited antipredator behaviour (decreased foraging and aggression, increased time on substrate) during both the conditioning and recognition phases. Those exposed to the stream water control did not exhibit any change in behaviour. Under weakly acidic conditions, we found no difference in any behavioural measure, either during conditioning or recognition trials for either experimental or control fish, demonstrating that salmon could not detect the alarm cue and hence were unable to learn to recognize the novel odour. These data provide the first field verification of chemically mediated acquired predator recognition learning and demonstrate that the ability to learn novel cues is impaired under weakly acidic conditions.
Key words: predator recognition, Atlantic salmon, chemical alarm cues, acid rain