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Platypoecilus maculatus is a viviparus fish belonging to subclass teleosteans (Fa. pociliidae) .Oogenesis in this Organism can be divided in to following stages. I- Clear Ooplasm with few organelles is covered with a layer of follicular cells. Appearence of the first Yolk droplets also Occured in this stage. II - microvilli forms and then a radiallayer appears between them. The development of of Covering layers is due to the activity of both; the oocyte and follicular Cells. In addition the perifèral vacuols appear in this Stage. III - Diffrentiation and strengthening of covering layers, continued and the fohhicular cells take columnar shape. Yolk storage of ooplasm also is increased.
IV - In this stage ooplasm is filled with yolk substance. The nuclear membrane is broken apart and as a result of oocyte growing, its membrane takes a smooth shape, and the microvilli length is decreased. Although in the Process of oocyte development the desmosomes do - not exist; after breading they appear in between the follicular cells. The fully grown oocyte is protected with four layers, where each layer play its specific role in physiology and protectiveness.