During post-larval development of Microcotyle sebastis, the ciliated epidermal jacket, ocellus, and larval opisthaptor are lost, and the clamps and genitalia develop. Microcotyle sebastis is protandrous and the genital elements develop in a specific order, following that of M. mormyri. The larval ciliated epidermal jacket and the four pairs of lateral hooks were shed by the "2 clamp-pair stage". The other hooks remain on the haptor and are lost between the 3 and 5 clamp-pair stage. As the clamps are then added, the genitalia develop and the intestinal branches extend. The 20 clamp-pair stage is reached within 12 days after hatching.
