Ultrastructural observation on genesis and morphology of cortical granules in Macrobrachium nipponense (Crustacea, Caridea).

Cortical granules are secretory vesicles in oocytes that develop from the Golgi complex. In the freshwater shrimp, Macrobrachium nipponense, mitochondria participates in the formation of cortical granules. We investigated the structural changes of mitochondria and the distribution cortical granules in different stages of oocyte development.

Formation of zona radiata and ultrastructural analysis of egg envelope during oogenesis of Chinese perch Siniperca chuatsi.

During oocyte maturation, egg envelope undergoes a series of changes in structure and function. We investigated the follicular envelope, zona radiata and plasmalemma of Chinese perch, Siniperca chuatsi at five different developmental stages by light, scanning and transmission electron microscopy. An octopus-like structure in the zona radiata was observed for the first time.