blastocoel

Initially, nephridial pair 4 resides roughly at the ankle of the sock, where it is folded over, and the larval esophagus and mid-gut reside entirely outside the sock; nephridial pairs 1-4 hang into the blastocoelic space from the unrolled leg, whereas pairs 5-7 reside inside the foot of the sock along with the larval hindgut (Fig.

hystera, most lipid reserves are extruded into the extracellular blastocoelic space at the gastrula stage by an apocrine mechanism, similar to that documented for the sea urchin Heliocidaris erythrogramma (Henry et al.

The larvae lack a digestive tract and have no coelomic and blastocoelic cavities (Woollacott and Zimmer, 1978).