Co-variation between the intensity of behavioural manipulation and parasite development time in an acanthocephalan-amphipod system.

摘要: Pomphorhynchus laevis, a fish acanthocephalan parasite, manipulates the behaviour of its gammarid intermediate host to increase trophic transmission definitive host. However, intensity behavioural manipulation is variable between individual gammarids and parasite populations. To elucidate causes this variability, we compared level phototaxis alteration induced by different sibships from one population, using experimental infections Gammarus pulex P. laevis. We used naive carried out our experiments in two steps, during spring winter. Moreover, also investigated co-variation (at stages infection, 'young' 'old cystacanth stage') other fitness-related traits, infectivity development time. Three main parameters could explain intra-population variation manipulation. The genetic variation, suggested differences families, was lower than owing an (unidentified) environmental factor. correlation found rate change, fastest growing parasites being unable induce rapid reversal. This suggests that cannot optimize at same time these important their fitness, part observed wild.