MORPHOLOGY AND GENERAL REPRODUCTIVE STAGES OF ...

24 Nucleolar stage. Chromatin nucleolar stage; a) nucleoli in
the nucleus present as chromatin form and more
numbers of nucleoli are visible (100x); b) nucleoli are
moving toward the nucleus periphery. Follicular layer
appear as purple stained layer surrounding the oocyte
(40x). Perinucleolar stage; a) Nucleoli allocated
peripherally to the nucleus. Cytoplasm is stained light
blue (20x); b) Dark spot granules can be observed
alongside the follicular layer. A sign of the formation of
granulosa layer (40x)
25 Cortical alveoli stage, a) Early cortical alveoli stage with
translucent dots at the peripheral oocyte indicating the
presence of yolk vesicles (40x); b) Follicular envelope
showing the developing vitelline membrane (100x); c)
More ‘round’ yolk vesicles are surrounding the ooplasm
periphery (20x); d) The prominent yolk vesicles are a
result of the coalescence of the prior yolk vesicles (100x)
26 Early vitellogenic stage; a) Formation of yolk globules
forming an eosin-stained ring around the nucleus (20x);
b) Yolk vesicles still remained at the peripheral ooplasm
(100x)
27 Vitellogenesis stage; a) Yolk globules filling up the
ooplasm (5x); b) Peripheral ooplasm is filled up with
smaller yolk globules, striated vitelline envelope is
evident (100x)
28 Late vitellogenesis stage; a) oil droplets present in the
ooplasm and the start of germinal vesicle breakdown
(10x); b) germinal vesicle leaves the nucleus and moves
towards the animal pole at the peripheral ooplasm and
yolk begins to coalesce (10x)
29 Atretic oocytes; a-b) atresia during cortical alveoli (20x);
c-d) atresia during vitellogenesis (40x); e-f) final stage of
atresia (100x and 20x, respectively)
30 Resting ovarian stage (from a sample of 1600g BW,
43cm SL and 0.25 GSI)
31 Ovarian development at GSI ≤ 1.0; a) Progressing -
maturing (from a sample of 910g BW, 45cm SL and 0.14
GSI); b) Regressing - spent (from a sample of 710g BW,
43cm SL and 0.44 GSI).
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