Stage 0 includes the formation of genital fold, the migration and accumulation of primordial germ cell and the formation of gonad. 0期,包括生殖嵴的形成,原始生殖细胞的迁移和积累以及性腺的形成期。
The primordial gonad, genital fold which composed of epithelial cells formed below the nephridium area 12 days after hatching. 鱼苗出膜12天,在其肾管区下方可见有一棒状突起,由上皮细胞构成,为生殖腺原基。