Fig. 1

Identification of ovaries at different developmental stages of P. clarkii. a-d: The morphology and color of ovaries at different stages by photograph; a: The morphology and color of the ovary at stage I, b: The morphology and color of the ovary at stage II, c: The morphology and color of the ovary at stage III, d: The morphology and color of the ovary at stage IV. E-H: The histomorphology of ovaries at different stages by HE staining; e: The oocytes at stage I, bar = 100 μm, f: The oocytes at stage II, bar = 100 μm, g: The oocytes at stage III, bar = 500 μm, h: The oocytes at stage IV, bar = 500 μm