Scott, J. A., Taylor, D. 2013. Effects of environment and enrichment on the behavior and serum corticosterone levels in Xenopus laevis. American Association for Laboratory Animal Science [AALAS] Meeting Official Program, 662 (Abstract #P145).

Xenopus laevis is a commonly used research animal for which well accepted enrichment strategies have not been established. Our overall objective was to identify enrichment strategies that are most beneficial to Xenopus as a step toward creating housing standards that effectively promote wellbeing. To measure preference for housing conditions, 16 Xenopus were housed in a single tank with half white and half black background. Additionally, lily pads and PVC pipe enrichment were added to each individual side, and then to both. Animals were observed and videotaped for 10 min under each condition. On average, frogs spent 64% of the time on the black side of the tank regardless of enrichment location, suggesting a preference for the dark background. When a frog purposely used the enrichment as cover for at least 5 s during the 10-min observation, it was considered one enrichment interaction. Out of 192 10-min observations, only 19 enrichment interactions occurred. With preference determined, 12 Xenopus were then placed into either black tanks with enrichment (DE) or white tanks with no enrichment (WN), with 6 animals per housing condition in groups of 3. Twelve frogs were also individually housed in DE and WN environments, with 6 per housing condition. After 7 d, blood was collected and is being analyzed for corticosterone levels. Out of 42 observations, singly housed Xenopus used enrichment daily with 37 enrichment interactions, whereas grouped housed Xenopus preferred to crowd together rather than use enrichment with only 9 enrichment interactions. Behavioral data collected to date, suggests that Xenopus prefer a dark background over a light background. When group-housed, interaction with enrichment is minimal compared with singly housed, suggesting that enrichment provisions are important for singly housed animals and less important for group-housed animals.