Skin-penetrating parasites and the release of alarm substances in juvenile rainbow trout |
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| Authors: | R. Poulin,§ ,D. J. Marcogliese,&dagger J. D. McLaughlin,&Dagger |
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| Affiliation: | Département des Sciences Biologiques, Universitédu Québec àMontréal, C.P. 8888, Succursale Centre-Ville, Montreal, Quebec, H3C 3P8;St Lawrence Centre, Environment Canada, 105 McGill St., 7th Floor, Montreal, Quebec, H2Y 2E7;Department of Biology, Concordia University, 1455 de Maisonneuve Blvd. W., Montreal, Quebec, H3G 1M8 Canada |
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| Abstract: | Juvenile trout Oncorhynchus mykiss did not react to the odours of Diplostomum sp. Cercariae alone, indicating that they were incapable of detecting the parasites directly. However, they increased the number of random darts as well as the amount of time spent motionless when exposed to the odours of a conspecific that was being infected by Diplostomum cercariae. These results suggest that even the minor damage inflicted by the cercariae to the fish's skin was enough to cause the release of alarm substances. The effectiveness of the fish's response with respect to the avoidance of parasites remains to be demonstrated. |
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| Keywords: | alarm substances Diplostomum Oncorhynchus mykiss parasite avoidance trematode cercariae |
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