The application segmentation outlines how zebrafish are deployed across distinct research domains, forming the core of the Zebrafish as a Model Organism segmentation framework. In drug discovery, zebrafish enable high‑throughput in vivo screening of compound libraries, accounting for roughly 35% of market value due to their translational relevance and cost efficiency. Toxicology applications—environmental and pharmaceutical safety testing—represent about 30%, leveraging the species’ rapid development and transparent embryos for acute toxicity endpoints. Neuroscience research, encompassing neurobehavioral assays and disease modeling, contributes approximately 20%, reflecting growing interest in neurodegenerative and psychiatric disorder studies. Developmental biology, focused on embryogenesis and organogenesis, comprises the remaining 15%, sustained by fundamental research funding and academic programs. These application segments collectively define the market taxonomy, with each proportion reflecting investment intensity, regulatory demand, and scientific priority across the zebrafish ecosystem.