Zebrafish are the second most used research vertebrate globally — their welfare deserves serious attention.
Zebrafish have become an enormously important research model because their transparent embryos, genetic tractability, and rapid development make them ideal for genetic and developmental studies. Their legal welfare status is often lower than mammals — in many countries, protection begins only at a specific developmental stage. Research shows zebrafish demonstrate learning, pain avoidance, and social preferences that are consistent with sentience. Applying the 3Rs to zebrafish research — including enriched housing, social grouping, and humane endpoints — improves both welfare and research quality.