Student Project Figures Figure 11 Schematic representation of the formation of a brood pouch in Botrylloides violaceus. (a) An oocyte is embedded in the mantle of an individual zooid and the brood pouch is present as an in-folding of the atrial epithelium. (b) The brood pouch envelops the fertilised egg, but a small area remains exposed to seawater. (c) The fertilised egg is surrounded by inner follicle cells and test cells, and the pouch is still attached to the atrial epithelium. (d) The brood pouch with the developing embryo is now embedded in the tunic and therefore separated from the internal components of the zooid. Image adapted from Zaniolo et al., 1998.  Figure 11 Figure 12 Figure 13