Visualization of strontium marking in dorsal fin rays of Megalobrama amblycephala for fish stocking

Hatchery release is a common and effective practice for protecting and restoring wild resources, and the success of the practice is commonly assessed using mark-recapture technology. We investigated the use of different dimensional X-ray imaging techniques for the strontium (Sr) marking of fish fin rays for stocking. Megalobrama amblycephala juveniles were marked by culturing specimens in 800-mg/L SrCl₂·6H₂O solution, the cross-sections of dorsal fin rays were subsequently obtained, and the concentrations Sr was analyzed by 2D imaging using an electron probe X-ray microanalyzer. Our preliminary findings indicate that the immersion marking method is effective for the Sr marking of fin rays in experimental fish. Moreover, we generated a bird’s-eye-view 3D mesh image of the Sr concentrations, which can provide a more comprehensive information for fish stocking than that using normal 2D imaging.