Author(s): Kousik Roy, Dipak Kumar Mandal

Abstract: Histological studies of the ovary of a carp, Labeo bata demonstrate the annual events of its ovarian function. The month wise studies reveal that oogonial proliferation and recruitment of primary oocytes occur during resting (November-December) and preparatory phase (January- February). Ovarian growth is coincided with the enhancement of temperature and photoperiod from the month of March when oocytes are characterised with the inclusion of yolk vesicles and yolk granules. These oocytes are transformed to yolky mature follicles during maturation phase (April to May) and attain the maximum oocyte diameter during spawning phase (June to August) after germinal vesicle breakdown. Ovary undergoes regression with decline of water temperature during September-October. Hypertrophid granulosa cells take active part in resorption of yolky oocytes. The new oogonia appear only after complete resorption of yolky oocytes. This study shows that photo-thermal conditions are the major regulator of the ovarian function in L. bata.

Pages: 19-24  |  1525 Views  287 Downloads

Download Full Article: Click Here