Does Circadian Rhythm Disorder Always Harm Organisms? Positive Effects of Circadian Rhythm Disorder in Lates calcarifer

摘要

Background and Objective: Circadian rhythm disorder was proved that may make a result of a wide variety of adverse health consequences, however, does circadian rhythm disorder always harm organisms in their whole life process? The aim of the present study was to evaluate the influence of circadian rhythm disorder on barramundi Lates calcarifer at different life stages. Materials and Methods: The growth and immune response s of larval and juvenile barramundi Lates calcarifer under various circadian rhythm disorder situation (13, 16, 19 and 24 h light time) were investigated in this experiment. Results: The results showed that total length of larval and juvenile significantly increased comparing to the control group when the light time was extended to 16 h, but the length of fish in 24 h light time group showed significantly lower than the control. The cortisol level of larvae in 16 and 19 h light time groups significantly differed from other 2 groups. To juvenile, circadian rhythm disorder didn’t make any influence on both T-SOD and ACP activity, the same result also appeared in cortisol concentration. The activity of three immune enzymes of larval from 16 and 19 h light time groups were all stimulated to increase by the homologous circadian rhythm disorder compared to the control. Conclusion: In brief, lightly circadian rhythm disorder (prolonged 3 h light times) can benefit in fish growth. Although it brought some immune response to larvae which may cause adverse effects, all these negative effects would be eliminated when they grow up to juvenile.