Abdominal 8th segment not entirely invaginated in the 7th. Their contraction causes the proboscis to be invaginated into its cavity. This vesicle will be subsequently invaginated by means of further inductions from the chordamesoderm. Inside the vesicular wall is an invaginated (facing inward) scolex. Further, the host cell wall becomes highly modified in the invaginated zone. The anammoxosome membrane is invaginated (folded in upon itself) to increase its surface area. Developing the highly invaginated ruffled membrane apposing the resorption compartment allows massive secretory activity. Once the endoderm cells were invaginated, the cells will keep moving beneath the ectoderm. Dense, compact DNA and a deeply invaginated membrane are characteristics of the species. Twenty hours after fertilization, a blastula with an invaginated pore at the vegetal pole forms. The rostellum remains invaginated in the apex of the organ. The invaginated pinocytosis vesicles are much smaller than those generated by phagocytosis. The ovipositor is clearly visible, partly invaginated in the seventh urite, which is always black. The anal plate is also a darker reddish-brown, and invaginated, forming a pouch. The invaginated margins form the rudiments of the lateral cusps of the AV valves.