## Abstract Although the rich variety of reproductive tract adaptations in elasmobranchs has been well documented and involves many variants associated with oviparity and extensive evolution of viviparity in the group, little is known of the hormone dependence of reproductive tract development, dif
Reproductive biology of elasmobranchs with emphasis on endocrines
โ Scribed by Fasano, Silvia ;Pierantoni, Riccardo ;Chieffi, Giovanni
- Publisher
- John Wiley and Sons
- Year
- 1989
- Tongue
- English
- Weight
- 897 KB
- Volume
- 252
- Category
- Article
- ISSN
- 0022-104X
No coin nor oath required. For personal study only.
โฆ Synopsis
The endocrinology of reproduction in elasmobranch fish has received a good deal of attention from comparative anatomists, histologists, and endocrine physiologists. This review deals with the gonadal morphology and the control of gonadal functions exerted via the hypothalamus-hypophysis axis and with how the gonads utilize or respond to putative local stimuli.
It is well known that, in the majority of vertebrate classes, gonadal functions are under hypothalamic control, whose secretory activity regulates the hypophysis. In elasmobranchs, a capillary system joining the hypothalamus to particular regions of the pituitary (rostral, median, and neurointermediate lobes) has been described, suggesting hypothalamic control of these lobes. Conversely, the ventral lobe, which produces gonadotropin, has no vascular contact with the hypothalamus. Recent papers argue for the existence of substances able to reach the pituitary ventral lobe via the general circulation, acting as gonadotropin-releasing factors. As for pituitary-gonadal This study was supported by grants 40% and 60% MP1,CNR 87.02371.74.
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