The dose makes the poison: Non-linear behavioural response to CO2-induced aquatic acidification in zebrafish (Danio rerio)

CO2-induced aquatic acidification is predicted to affect fish neuronal GABAA receptors leading widespread behavioural alterations. However, the large variability in magnitude and direction of responses suggests substantial species-specific CO2 threshold differences, life history parental acclimation effects, experimental artifacts, or a combination these factors. As an established model organism, zebrafish (Danio rerio) can be reared under stable conditions for multiple generations, which may help control some observed wild-caught fishes. Here, we used two standardized tests investigate effect 1-week acclimatization four pCO2 levels on anxiety-like behaviour, exploratory locomotion. Fish acclimatized 900 μatm demonstrated increased behaviour compared (~480 μatm), however, exposed 2200 was indistinguishable from that controls. In addition, 4200 had decreased behaviour; i.e. opposite response than treatment. On other hand, did not differ among any exposures were tested. Thus, elevated are linear; with potential important implications physiological, environmental, studies.