Suspended Arrays Improve Rainbow Trout Growth during Hatchery Rearing in Circular Tanks

Environmental enrichment can be an effective tool to improve rearing efficiencies during hatchery production. This study evaluated the effectiveness of two different vertically-suspended arrays in circular tanks on the growth of juvenile rainbow trout Oncorhynchus mykiss. Treatments consisted of an array of suspended aluminum rods, an array of suspended aluminum angles, or no suspended structures (control) in this 141 day study. Weight gain and feed conversion ratio were significantly improved in fish reared in tanks containing either of the suspended structures compared to unenriched control tanks. The use of either vertical rods or angles is recommended during rainbow trout rearing in circular tanks, although using angles may be more desirable because they require less material to construct.