Vitellogenesis in the oocytes of B. areolata involves both autosynthetic and heterosynthetic processes, whereas
many species in the caenogastropods such as the nassariid I. obsoleta (Taylor and Anderson 1969), muricid
B. brandaris (Amor et al. 2004) and buccinid Neptunea (barbitonia) arthritica cumingii (Chung et al. 2006) formed
their yolk bodies only by autosynthesis. In B. areolata, this process is involved with the combined activities among
proteosynthetic organelles including RER and Golgi bodies. As vitellogenesis proceeds in B. areolata, the production of yolk bodies via autosynthesis is sometimes complemented by multivesicular bodies, similar to those in I. obsoleta (Gerin 1976) and N. arthritica cumingii (Chung et al. 2006); unfortunately, it is not possible to determine how the multivesicular bodies originate. However in most gastropods, their yolk formation via heterosynthesis involving endocytosis is less widespread than that produced by autosynthesis, and this seems to be confined to some caenogastropods like the buccinid C. stimpsoni (West 1981) and the neritid Bathynerita naticoidea (Eckelbarger and Young 1997), the patellogastropods, Patella spp. and Helcion pectunculus (Hodgson and Eckelbarger 2000) as well as the pulmonate, Siphonaria serrata (Pal and
Hodgson 2002). In B. areolata, endocytotic activity is detected by the presence of endocytotic pits and vesicles
that gradually fuse to form yolk bodies. The appearance of these pits probably indicates the uptake of extra-ovarian
substances, but their origin has still to be identified.