How welfare standards for zebrafish in biomedical research are developing as this species becomes an increasingly important research model.
Zebrafish welfare in research has emerged as an important and sometimes underappreciated field as the species has risen to prominence in biomedical laboratories. The historical perception that fish are less sentient than mammals has led to welfare standards that lagged behind those for rodents, even as evidence for fish pain and stress has grown substantially. Zebrafish show avoidance learning, stress responses measurable by cortisol levels, and clear social preferences that affect their wellbeing. The dramatic increase in zebrafish use — driven partly by their perceived lesser moral status compared to mammals — makes it essential that welfare standards evolve to match the scientific evidence.