Short Article
A.K. Pandey
Abstract
The steadily growing importance of culture fisheries during the recent years has stimulated to improve the techniques necessary for securing the basic requirement, production of young ones (fry and fingerlings) for stocking. Therefore, the artificial propagation technique needs constant refinement for obtaining quality fish seed at the desired times of year. Recent advances in fish endocrinology have led to a better understanding of the hormonal factors involved in the control of gamete production, mode of their action and regulation of secretions during different phases of reproductive cycle. Environmental stimuli like photoperiod and temperature are perceived by the brain which releases gonadotropin-releasing hormone (GnRH). Though GnRH appeared first in cnidarians (coelenterates), it has also been recorded from molluscs, echinoderms and protochordates. This neuro-peptide (10 amino acids) has also been reported from non-hypothalamus tissues where it perform autocrine/paracrine functions.