Zebrafish are increasingly important research models, with group housing and environmental enrichment significantly improving welfare outcomes compared to isolated individual housing.
Zebrafish welfare has become increasingly important as their use in biomedical research has grown enormously. As shoaling fish, isolation creates significant stress that may compromise research validity alongside creating welfare harm. The scientific case for group housing - producing lower baseline stress and more naturalistic behavior - aligns with the welfare case, creating a situation where ethics and research quality point in the same direction. The evidence for zebrafish pain responses is now sufficient to require consideration of analgesia for painful procedures, representing an important welfare advance for this commonly overlooked research species.