Typical gonad characteristics at different stages of M albus gonadal development. Gonad histology revealed M albus sex change from female (oocytes at all known developmental stages) to male (mature sperm in the gonad) via intersex by hematoxylin and eosin staining of the ovary, ovotestis, and testis. Scale (in each graph), 100 μm. ct, connective tissue; dg, degenerating oocyte; is, interstitial tissue; O, oocytes; O_I, oocytes at stage I; O_II, oocyte at stage II; O_III, oocyte at stage III; sm, seminiferous; sz, spermatozoa.