Zebrafish have become one of the most important model organisms in biomedical research. Ensuring their welfare in laboratory settings is both a scientific and ethical priority.
Zebrafish welfare in research is an emerging priority as evidence of their sentience and stress responsiveness accumulates. Standard laboratory housing in small tanks with minimal environmental complexity fails to meet the social and behavioural needs of a highly active schooling species. Painful or distressing procedures performed on larvae are sometimes justified on the basis of early developmental stage — but larvae show nociceptive responses from surprisingly early developmental points. Welfare-conscious zebrafish research requires enriched housing, social grouping, and rigorous humane endpoint application.