Ultrastructural study of oogenesis in the acotylean Echinoplana celerrima, (Platyhelminthes, Polycladida)

摘要

Here, the ultrastructure of the female gonad of the marine polyclad Echinoplana celerrima was investigated using both light and electron microscopy. The female gonads are dispersed in the dorsal parenchyma between the digestive ramifications. Each ovary is separated from adjacent tissues by a homogeneous basal lamina and is characterized by the presence of a germinative zone, growing oocytes at the previtellogenic stage, and at the vitellogenic stage.