To investigate the phenotypic alterations in the ovaries of miR-187 knockout (KO) fish, a 3D imaging analysis of wild-type and mutant ovaries was performed at two key developmental stages: before (104 days post-fertilization, dpf) and during (211 dpf) the reproductive period. Ovarian follicle diameters were extracted from the 3D image datasets, enabling the characterization and comparison of follicle size distribution profiles across genotypes and developmental time points.