stomodeum
- 网络口凹;口管;原始口腔;囊胚层缩起形成原口;原口
stomodeum-
In the course of development , the invagination of stomodeum occurs earlier than that of proctodeum at the third and the sixth nauplius stages respectively .
在发育过程中，口凹是在第三期无节幼虫时内陷形成，而原肛是在第六期无节幼虫时内陷形成的，所以口凹的发生早于原肛的发生。
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The putative PGCs with Cf-vasa expression form in gastrula stage , and are located symmetrically at both sides of the stomodeum in trochophore . These cells subsequently migrate to the posterior pole of D-shaped larva and then migrate towards abdomen .
表达Cf-vasa的原生殖细胞形成于原肠胚时期，在担轮幼虫中对称分布于口凹两侧，并随幼虫发育迁移至D型幼虫末端后，继续沿边缘向腹面迁移。