Zebrafish are the second most commonly used vertebrate in UK research. Their welfare needs are increasingly recognised as requiring the same systematic attention given to mammals.
Zebrafish welfare has historically received less attention than mammalian research animal welfare, partly because of assumptions about fish sentience that the evidence no longer supports. The 3Rs framework - Replacement, Reduction, and Refinement - applies to zebrafish as it does to mammals, and refinement opportunities are numerous and often low-cost. Social housing, environmental enrichment, and careful anaesthetic and euthanasia protocols represent achievable improvements. As zebrafish use continues to grow, building welfare science alongside their use as research models is both ethically required and scientifically beneficial.