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3.1.35. Hormones involved in reproduction and their sources transaction of external signal
The External environment where the fish is living plays vital role in inducing the animal to go for maturation. Photoperiod (the duration / or length of day time) plays important role in maturation of animals. The pineal organ through the photoreceptor cells and other environmental culs produce electrical pulse which includes the production of melatonin from Nacetyl serotomin in the presence of hydroxyindole–O-methyl transferare an enzyme. This organ in fishes mediates photoperiod control of gonadal activity, which involves the pineal hormone melat and the regulation of diurnal cycle of gonada release. Illustration Spring spawner normally breed during the lengthier photoperiod where as the winter spawner breed during only shorter photoperiod. Mechanism involved in maturation and ovulation Egg development and Endocrine regulation Steroids in the male :
Produced steroids
Antrogen Testosterone, 11 oxyhydrogenated androgen 11 keto testosterone
Progestins Produced in the testis 17 µ hysony 20 ß dihydro progesterons – peak occur after fertilization and before the onset of spermiation. It involves in spermiation process by conrolling ionic composition in the seminial fluid and involves in spawn behaviour of male and female. Steroid conjugates
Glucuronidation is the process to eliminate steroids by converting into water soluble and thus more readily excretable products function as sex pheromones. Endocrine regulation of spermatogenesis and secondary sexual characteristics Gonadal regression Attesia of garmetes occur if the normal levels of hormones are disturbed. Altesia is involved in the removal of unused gametes after the spawning season; any may be related to the change in hormone level after spawning. Factors inhabiting reporduction |