Zebrafish have become one of the most widely used vertebrate research models, but their welfare needs have historically received less attention than those of mammals despite their capacity for pain and stress.
The rapid growth of zebrafish use in research has outpaced development of welfare standards. These animals can experience chronic stress from suboptimal water quality, overcrowding, inadequate social housing, and repeated handling. Pain during procedures such as fin clips and injections requires appropriate analgesia. Institutions should develop species-specific welfare protocols that account for zebrafish sensory capabilities, social needs, and environmental requirements rather than applying mammal-centric care frameworks.