Effects of acclimatisation on behavioural repeatability in two behaviour assays of the guppy Poecilia reticulata

摘要

Establishing behavioural repeatability is important in animal personality research; however, a range of factors can influence repeatability. Experimental design, particularly acclimation time, is important in managing a subject's stress prior to the onset of behavioural observations. Acclimatisation also ensures we capture normal behaviour and promotes consistency in the subject's responses between observations. The importance of acclimatisation prior to an assay is widely recognised by animal researchers; however, acclimation time varies dramatically across personality studies. Here, we investigated the effects of acclimatisation time on the repeatability of activity and emergence behaviour in feral and domestic populations of lab-reared guppy, Poecilia reticulata. Contrary with expectations and previous findings, we found highest repeatability in guppy activity levels after 2h of acclimation to the test arena. In the emergence assay, fish exposed to 10min of acclimatisation showed highest repeatability; however, all acclimation periods produced high repeatability, suggesting that the emergence assay generates robust behavioural responses irrespective of acclimation time. The outcomes were broadly consistent across both populations. These results show that methodology can impact the findings of animal personality research and needs to be considered carefully for each assay. We recommend that researchers investigate appropriate acclimatisation times for their study species prior to commencing research.Significance statementAnimal personality is individual differences in behaviour that are maintained through time and across contexts. Thus, demonstrating the repeatability of behavioural differences between individuals is imperative to establishing animal personality. To estimate repeatability, individuals are assessed multiple times on the same task to ensure there are consistent differences between individuals. When carrying out repeated observations, acclimatisation time should be considered to minimise stress levels of an animal prior to the behavioural assay. We assessed a range of acclimation times on emergence and activity behaviour in two populations of guppies. While individual variation in emergence behaviour was repeatable across a range of acclimation times, activity levels in guppies became significantly more repeatable after 2h of acclimatisation. These results show that considering proper acclimation time is important when performing behavioural experiments and should be properly calibrated by researchers prior to conducting personality research.