Author(s): Kundu S and Chakrabarti P

Abstract: In the present study, it was found that the thyroid follicles of Puntius sarana (Hamilton) were in the form of groups of follicles around the anterior median extension of the ventral aorta in the sub-pharyngeal region between the connective tissues in close association with blood capillaries. The number of follicles was extremely low. Two types of follicles have been identified – the smaller follicles and the large follicles. The thyroid follicles in P. sarana was unencapsulated and therefore, capable of widespread ectopic growth as evidenced by active migration of the follicles in head kidney adjacent to blood vessels. The lumen of the follicles were either fully or partially filled up with the agranular eosinophilic or aniline blue positive colloidal materials or encircled by a single layer of epithelial cells. The low active condition of the thyroid follicles during the growth phase i.e. December to February was well in coincidence with the increase of early and late perinucleolar oocytes. During maturation phase i.e. March to May, the colloids were faintly stained having resorption vacuoles as well as vacuolated structure at the outer margin of the colloid. These features were well correlated with the occurrence of cortical alveolus and yolk granule stages in the ovary. The most active condition of the thyroid follicles were noted during spawning phase i.e. June to August as revealed by the maximum follicular cell diameter and also correlated with the dynamic cytological activities during vitellogenesis and highest frequency percentage of mature oocytes in the ovary. It was concluded that the cytological changes in the thyroid follicles and ovarian activities correlate well during growth, maturation and spawning phases in Puntius sarana.

Pages: 318-322  |  1238 Views  76 Downloads

Download Full Article: Click Here