Impact of tank background on the welfare of the African clawed frog, Xenopus laevis (Daudin)

• Published in: Applied animal behaviour science Vol. 185; pp. 131 - 136
• Main Authors: Holmes, Andrew M., Emmans, Christopher J., Jones, Niall, Coleman, Robert, Smith, Tessa E., Hosie, Charlotte A.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.12.2016
• Subjects: Animal welfare; Anura; Behaviour; Corticosterone; Enrichment; Tank background; Xenopus; Xenopus laevis; Enrichment; Xenopus; Animal welfare; Behaviour; Corticosterone; Tank background
• ISSN: 0168-1591; 1872-9045
• DOI: 10.1016/j.applanim.2016.09.005

•Study compared tank background colours for laboratory housed Xenopus laevis.•Water-borne corticosterone lower when housed with ecologically relevant background.•Fewer atypical active behaviours when housed with ecologically relevant background.•Non-ecologically relevant background led to greater loss of body mass.•Tank background refinement may improve captive welfare in this common model species. 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.