Note
The ultrastructural features of the ovary and oogenesis have been examined in the neritid gastropod Bathynerita naticoidea, a bathyal species endemic to oil and gas seeps in the Gulf of Mexico. This is the first ultrastructural study of vitellogenesis in any archaeogastropod. The ovary is an acinous organ containing oocytes in all stages of oogenesis. Oocytes are closely associated with hypertrophic follicle cells that may playa role in oocyte nutrition. Vitellogenesis is a complex process involving both autosynthetic and heterosynthetic pathways that contribute to the formation of at least three types of yolk bodies.