TY - JOUR
T1 - Learning to recognize novel predators under weakly acidic conditions
T2 - The effects of reduced pH on acquired predator recognition by juvenile rainbow trout
AU - Leduc, Antoine O.H.C.
AU - Ferrari, Maud C.O.
AU - Kelly, Jocelyn M.
AU - Brown, Grant E.
N1 - Funding Information:
We would like to thank Drs. James Grant and Reehan Mirza for their comments on the manuscript, and Justin Golub, Mark Harvey, Patricia Foam and Isabelle Désormeaux for their help with the maintenance of fish. Financial support was provided by NSERC of Canada and Concordia University to G.E.B. All work reported herein was in accordance with Concordia University Animal Care Committee protocol #AC-2002-BROW.
PY - 2004
Y1 - 2004
N2 - Recent studies have demonstrated that under weakly acidic conditions (pH 6.0), many prey fishes, including juvenile rainbow trout (Onchorhynchus mykiss), do not exhibit overt antipredator responses to conspecific chemical alarm cues. In laboratory trials, we investigated the potential effects of reduced pH on the ability of hatchery reared, predator naïve juvenile rainbow trout to acquire the recognition of a novel predator (yellow perch, Perca flavenscens). Initially, we exposed trout to the odour of a predatory yellow perch, buffered to pH 6.0 (weakly acidic) or pH 7.0 (neutral) paired with conspecific skin extracts (also buffered to pH 6.0 or 7.0) or a distilled water control. Juvenile trout exhibited significant increase in antipredator behaviour when exposed to neutral skin extract (pH 7.0). When retested 48 hours later to perch odour alone (pH 7.0), only trout initially conditioned with neutral skin extracts (pairs with either neutral or acidic perch odour) exhibited a learned recognition of perch odour as a predator risk. Those initially exposed to weakly acidic skin extract or the distilled water control did not show a learned response to predator odour. These results demonstrate that the ability to acquire the recognition of novel predators is impaired under weakly acidic conditions, as would occur in natural waterways affected by acidic precipitation.
AB - Recent studies have demonstrated that under weakly acidic conditions (pH 6.0), many prey fishes, including juvenile rainbow trout (Onchorhynchus mykiss), do not exhibit overt antipredator responses to conspecific chemical alarm cues. In laboratory trials, we investigated the potential effects of reduced pH on the ability of hatchery reared, predator naïve juvenile rainbow trout to acquire the recognition of a novel predator (yellow perch, Perca flavenscens). Initially, we exposed trout to the odour of a predatory yellow perch, buffered to pH 6.0 (weakly acidic) or pH 7.0 (neutral) paired with conspecific skin extracts (also buffered to pH 6.0 or 7.0) or a distilled water control. Juvenile trout exhibited significant increase in antipredator behaviour when exposed to neutral skin extract (pH 7.0). When retested 48 hours later to perch odour alone (pH 7.0), only trout initially conditioned with neutral skin extracts (pairs with either neutral or acidic perch odour) exhibited a learned recognition of perch odour as a predator risk. Those initially exposed to weakly acidic skin extract or the distilled water control did not show a learned response to predator odour. These results demonstrate that the ability to acquire the recognition of novel predators is impaired under weakly acidic conditions, as would occur in natural waterways affected by acidic precipitation.
KW - Acid rain
KW - Acquired predator recognition
KW - Antipredator behaviour
KW - Chemical alarm cues
KW - Rainbow trout
KW - Salmonids
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U2 - 10.1007/s00049-003-0268-7
DO - 10.1007/s00049-003-0268-7
M3 - Article
AN - SCOPUS:1842786529
SN - 0937-7409
VL - 14
SP - 107
EP - 112
JO - Chemoecology
JF - Chemoecology
IS - 2
ER -