Background. Farmed fish reared in aquaculture systems are exposed to physiological stressors from biological, chemical, and physical sources. The consequences of these stressors affect the productivity of farming outcomes by reducing immune response, growth, and development within fish. A 24-h study was performed to determine the effects of supplementing puerarin—the most biologically active ingredient present in the roots of kudzu (Pueraria lobata)—within farmed fish on acute handling stress. Materials and methods. Fingerlings of Chinook salmon, Oncorhynchus tshawytscha, were maintained at 16–18ºC in 10 US gallon (37.8 L) glass tanks, supplied with recirculated and aerated dechlorinated water. Puerarin was given to fish through supplementation to commercial fish feed pellets. Acute handling stress was induced through transferring the fish from their housing tanks into 8 designated tanks at 0000 h. Subsequently, at 5 h post-transfer all the fish were fed to satiation, following which the stressed groups were chased with nets. Results. The results indicated that administration of puerarin through feed supplementation reduces plasma glucose, hematocrit, plasma protein, and improves spleen somatic indices after 24 h, and thereby counteracting the negative consequences of acute stress induced through handling. Conclusion. The results suggest that supplementation of puerarin to commercial fish feed improved overall fish health through enhancing systemic circulation while attenuating plasma glucose. Being one of the first studies to study the effects of puerarin on fish, our results are in agreement with prior research with puerarin on other animal models.

salmon, aquaculture, stress, puerarin