Poecilia reticulata (Peters, 1859)

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

2.1 | P. reticulata population

We used second-generation laboratory-born male and female P. reticulata from parents that had been originally collected from a low-predation environment, with only one species of predator, Rivulus hartii located in the upper Turure River (GPS coordinates: 10.6903,

61.1638) and transported in March 2015 to our laboratory in Montréal , Canada. One week before the start of the experiment, individuals were haphazardly selected and assigned to two tanks of 10 fish each for acclimation. These tanks were kept in a room with natural light and contained artificial gravel at the bottom and a piece of broken flowerpot for shelter. Temperature was not measured in these tanks. The fish were fed daily with ad libitum brine shrimp throughout the experiment. One fish in each group died before the experiment, leaving us with nine fish per group (six females and three males). Each fish was weighed after the first and the second rheotaxis trials. Just after the first rheotaxis trial and for the duration of the experiment, each individual was isolated and maintained in a 1.8-L tank within a flow-through system (Aquaneering Inc., San Diego, CA, USA). Immediately after the end of the experiment, fish were returned to a “retirement stock tank” with conspecifics .