Experimental infection of Arctic charr Salvelinus alpinus (L.) with the cercariae of diplostomid eye flukes Diplostomum spp.

摘要

The aim of the present study was to quantify the relative importance of dose and exposure time in the experimental infection of Arctic charr with the cercariae of Diplostomum spp. To reach the aim, 15-month-old Arctic charr (n=19) were exposed singly to 100-3300 parasite cercariae (range) for 110-1225 seconds (range) at 17 degrees C. The number of parasites located themselves in the fish eye lenses as a result of the experimental infection correlated positively both with the number of parasite cercariae in the exposure (dose) and the exposure duration (time). A linear model having the number of parasites located in the fish as dependent variable and dose and time as independent variables explained 85% of the original variation in the dependent variable. Adding fish size as an independent variable did not improve the model's explanatory power. To conclude, the outcome of the experimental infection of Arctic charr with Diplostomum spp. is predictable, when experimental conditions are standardized and the parasite challenge is well-controlled. The present results can serve as a reference for any experimental infection of Arctic charr with Diplostomum spp.