Repeatability of lateralisation in mosquitofish Gambusia holbrooki despite evidence for turn alternation in detour tests

Detecting behavioural lateralisation in Poecilia reticulata is strongly dependent on experimental design

“…Higher repeatability was, however, presented in McLean and Morrell (2020) in terms of relative laterality in an I-maze assay with 48-h intervals between testing of P. reticulata (males: R = 0.324 ± 0.116, females: 0.363 ± 0.115), but was markedly less repeatable for absolute laterality (males: R = 0.252 ± 0.110, female: R = 0.124 ± 0.095). Vinogradov et al (2021) similarly found relative laterality in female Gambusia holbrooki to be significantly repeatable in five of six treatments incorporating social and control stimuli (R = 0.280-0.623) and non-repeatable in only one assessed treatment (R = 0.036). Therefore, while consistency was identified between the two 'motor' detour assays in the current study, repeatability of these results over time is brought into question.…”

“…Bisazza et al (2001) selectively bred Girardinus falcatus from right and left-aligned parentage and found the two groups to consistently display an opposite direction of lateralisation between the five lateralisation assays investigated: turns in an I-maze, rotation in a circular arena, female shoaling (mirror assay), male sexual behaviour (I-maze) and male agonistic behaviour (mirror assay). However, Roche et al ( 2020) and Vinogradov et al (2021) found contrasting repeatability results to each other even when using a similar 'motor' I-maze assay to assess relative lateralisation. Perhaps use of a stimulus with stronger selection pressure through salience and valence, such as a predatory or social stimulus, may increase repeatability (Friedlaender et al 2017;Roche et al 2020;Vinogradov et al 2021).…”

“…However, Roche et al ( 2020) and Vinogradov et al (2021) found contrasting repeatability results to each other even when using a similar 'motor' I-maze assay to assess relative lateralisation. Perhaps use of a stimulus with stronger selection pressure through salience and valence, such as a predatory or social stimulus, may increase repeatability (Friedlaender et al 2017;Roche et al 2020;Vinogradov et al 2021). Bell et al (2009) suggest that behaviours which are more sensitive to environmental or motivational influences may be less repeatable, such as those influenced by energetic needs (MacGregor et al 2021), social interactions (Bevan et al 2018) or ecological variables (Castellano et al 2002;Smith and Hunter 2005).…”

“…This may also elicit a more stress-induced response in individuals where this is used (Fanouraki et al 2011;Pavlidis et al 2015). Recent research has identified that use of such encouragement increased repeatability in relative lateralisation and the proportion of left turns selected (Vinogradov et al 2021). Therefore, this approach was not utilised in the current study, rather the duration of the trial was increased 6 allowing the subjects to engage with the apparatus in their own time to achieve an adequate number of turns per trial without introducing potential bias.…”

“…Given the wide variety of current methodologies investigating lateralisation in a range of species and disparate results produced from these studies, it is important to assess whether differing methodologies produce consistent, and therefore repeatable, laterality indexes while holding other variables, such as the test species, constant. Repeatability within even an I-maze assay has been recently brought into question (Roche et al 2020;Vinogradov et al 2021) and, therefore, assessment of the consistency of results produced from different assays is essential.…”