Melatonin

Almost all the organisms have adapted their behaviours and biological functions to diurnal and seasonal change in environmental cues such as light-dark cycle, temperature, food availability, etc. (Falcon et al. 2010b). Melatonin is the only chronobiotic molecule which transduces the environmental cues into the chemical signal by rhythmic variation in its release and level. Thus the diurnal and seasonal changes in the circulating levels of melatonin provide the information about the time of day and season, allowing the organism to synchronize their metabolism, physiology, and behaviour to the variations of the environmental cues (Falcón et al. 2007, Falcon, Migaud, Munoz-Cueto and Carrillo 2010b). In fish, the changes in temperature can influence the amplitude of the melatonin rhythm, which provides the organism with accurate information about the season (Iigo and Aida 1995). …show more content…
A few studies are available in temperate teleost fish, and the information about the tropical fish far lacks behind. The production of melatonin, the multitasking molecule (Reiter et al. 2010b) is directly linked to the environmental photo-thermal conditions. The effect of these abiotic factors on the transcriptional profile of melatonin bio-synthesizing enzyme genes in pineal and retina is scarce. Accordingly, further study on the molecular mechanisms of melatonin biosynthesis in the pineal as well as non-pineal tissues has remarkable implication in understanding the physiology of melatonin particularly in the context of regulation of reproduction in any commercially important fish species like carp in