Gallissian, M.-F.; Vacelet, J. (1992). Ultrastructure of the oocyte and embryo of the calcified sponge, Petrobiona massiliana (Porifera, Calcarea). Zoomorphology. 112: 133-141.
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Gallissian, M.-F.; Vacelet, J.
1992
Ultrastructure of the oocyte and embryo of the calcified sponge, <i>Petrobiona massiliana</i> (Porifera, Calcarea)
Zoomorphology
112: 133-141
Publication
Available for editors
In the sponge Petrobiona massiliana, a Calcarea related to "pharetronid" fossils, the oocyte and the embryo both receive an unusual amount of maternal nurse cells. Yolk granules are large and display a lamellar structure throughout the entire growth period, which allows them to be used as markers of the oocyte reserves. The cruciform cells (" cellules en croix") of the embryo appear to degenerate at an early stage. These features are compared to those found in other Calcarea.
