Muhammad, Nazir Bhatti (1972) THE REPRODUCTIVE PHYSIOLOGY OF THE TELEOST, COLISA FASCIATA (BLOCH AND SCHNEIDER). Doctoral thesis, University of the Punjab.

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The annual cyclical changes in the gametogenetic activity of gonads of Colisa fasciata (Bloch and Schneider) were studied on the basis of gone somatic index and histology of the gonads. The process of vitellogenesis in the ovary has been associated with the nucleolus like structures, the vitellonucleoli in the nucleus of the oocyte. The secretion of male sex hormones has been attributed to the interstitial cells in the testis. In the ovary, two types of endocrine sources have been observed, i.e., the pre-ovulatory, and 'post-ovulatory ' cor**ra formed by the granulose cells. The cyclical changes in the pituitary gland were studied and the gonad tropic activity was found to be localized in the cyanophilic gonadotrophs in the meso-adenohyophysis. The gonadotrophs were differentiated from the thyrotrophs on the basis of size, the gonadotrophs being larger. The identity of these cells was further confirmed by thiourea treatment which resulted in hypertrophy and hyperplasia throtrophs. The gonadotrophs were observed to show numerical variations in correlation with the gonadal cycles. The pituitary gonadotrophs and the gonads were observed to correspond to the environmental temperature and daylight. The effects of administration of an inhibitor of pituitary gonadtroins, methallibure, I.C.I. 33.828 (a dithiocarbamoylhydrazine derivative) on the gonads and the methallibure was on effective inhibitor of pituitary gonadotropins in colisa fasciata also. A comparison was made of the effects of piscine pituitary extracts, and purified mammalian pituitary gonadotropins on the methallibure treated as well as normal fish. The pituitary extracts were found to be more effective than the purified mammalian pituitary hormones. The methallibure treated animals gave more conclusive results than the normal ones. FSH alone produced no effects on the pituitary and gonads, whereas LH produced significant activation of the gonads. The administration of FSH and LH combined (1:1) produced more significant stimulation of pituitary and gonada than LH alien. The identity of the pituitary gonadotropins of the fish understudy has been discussed.

Item Type: Thesis (Doctoral)
Uncontrolled Keywords: teleost, colisa fasciata, spermatogenetic cells, thiourea treatment, methallibure, piscine pituitary extracts, mammalian pituitary gonadothropins, vitellogenesis
Subjects: Q Science > QL Zoology
Depositing User: Muhammad Khan Khan
Date Deposited: 27 Oct 2016 04:18
Last Modified: 27 Oct 2016 04:18

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