Holmes, A. M., Emmans, C. J., Jones, N. et al. 2016. Impact of tank background on the welfare of the African clawed frog, Xenopus laevis (Daudin). Applied Animal Behaviour Science 185, 131-136.

The captive environment of a laboratory animal can profoundly influence its welfare and the scientific validity of research produced. The African clawed frog (Xenopus laevis) is a common model organism, however current husbandry guidelines lack supporting quantitative evidence. The visual environment is a fundamental aspect of a captive animal’s housing and may affect a number of physiological and behavioural responses. This is particularly important for species such as X. laevis where cryptic camouflage is a fundamental defence mechanism. Here male (n=16) and female (n=20) X. laevis were housed in tanks with ecologically relevant (black) and non-relevant (white) background colours and physiological and behavioural responses observed. Higher levels of water-borne corticosterone were observed in tanks with a white background compared to a black background in females (p=0.047). Increased atypical active behaviours (Swimming: p=0.042; Walling: p=0.042) and a greater degree of body mass loss (p<0.001) were also observed in the white background condition. Together these responses are indicative of increased stress of X. laevis when housed in tanks with a non-ecologically relevant background compared to an ecologically relevant background and suggest refined tank background colour may improve welfare in this species.