Gyrodactylus

Blondel, L., Klemet-N'Guessan, S., Hendry, A. P. & Scott, Marilyn E., 2024, Parasite load, rather than parasite presence, decreases upstream movement in Trinidadian guppies Poecilia reticulata, Journal of Fish Biology 105 (1), pp. 177-185 : 178

2.2 | Gyrodactylus population and infection protocol

A laboratory isogenic strain of G. turnbulli that had been obtained from a local pet store and maintained in a stock fish population in our laboratory since 2013 ( Tadiri et al., 2013, 2016) was used as the source of infection. We used one infected female fish from the parasite-infected stock population as the donor to infect all recipient fish. Donor and recipients were anaesthetized in a solution of 0.02% Tricaine methanesulfonate (MS-222). We used a standard infection procedure ( Scott, 1982). In brief, under a dissecting microscope, we used tweezers to transport a scale with an attached parasite from the donor fish to the caudal fin of the recipient. Subsequently, we visually confirmed that the parasite was attached to its new host. The whole procedure lasted less than 2 min per fish and was performed only once. Infection dynamics were recorded every second day on anaesthetized individuals using a dissecting microscope to count the number of Gyrodactylus parasites. This procedure lasted less than 2 min per fish. All control fish were anaesthetized for sham infection every 2 days, so that they went through the same procedures as the infected fish. Approval for animal care and research was obtained from the McGill University Animal Care Committee (AUP 2014-7547) in compliance with the Canadian Council on Animal Care.