Seasonal Plasma Cortisol Level of Amur Common Carp among different Age Groups in Tarai Region of Uttarakhand

Author: Ningthoukhongjam Soranganba

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Abstract

Environmental and culture induced stressor like seasonal change in water parameters and handling of brooder are the major precursor for increased in cortisol level leading to detrimental effect on well-being especially growth and reproduction. The study was carried out to assess the cortisol levels of amur common carp in four seasons (spring, summer, autumn and winter)among three different age groups (0+, 1+ and 2+ years) using the RP-HPLC method with relation to its reproductive performance. The assumption on homogeneity of variances was tested and not satisfied based on Levene’s F test, F (19, 78) = 4.761, p< 0.05. Age has a very significant effect on the plasma cortisol concentration among different group of the species, F (4, 98) = 2846.238, p <0.05, η2 = 0.993. Seasonal changes also showed significant effect in plasma cortisol concentration of the species, F (3, 98) = 5157.560, p <0.05, η2 = 0.995. The interaction between the different age groups and seasonal changes was also highly significant for Amur common carp, F (12, 98) = 441.040, p <0.05, η2 = 0.985. Since age and season has significant effect on the plasma cortisol concentration of the species, a Tukey’s HSD post-hoc test found statistically significance between the means of all seasons. Between age groups, the means between male 1+ (37.87±8.46ng/ml) and female 1+ (37.65±2.51ng/ml) were not significant while the means between the remaining age groups were statistically significant (p<0.05). The plasma cortisol level was significantly correlated with gonado-somatic index (r = 0.751, p< 0.01) while non-correlation with hepato-somatic index (r = -0.554, p< 0.01). Plasma cortisol in all the age groups showed highest concentration in concomitant with breeding seasons. Highest level of cortisol was observed during spring season followed by summer, autumn and winter season in which male with older age group (2+ year old) dominated the plasma cortisol level followed by female 2+, male 1+, female 1+ and 0+ year old respectively. The above findings reveal that stress hormone - cortisol is instrumental in reproductive process however care must be taken not to augment secondary stressor from fish husbandry and handling processes.

Keywords

Amur common carp, cortisol, seasonal reproduction, Tarai region

Conclusion

Plasma cortisol studied in all the age groups has highest level concomitant with other sex hormone and breeding seasons. Highest level was observed during spring season followed by summer, autumn and winter season. Male 2+ year old dominated the plasma cortisol level followed by female 2+, male 1+, female 1+ and 0+ year old groups respectively. Cortisol being a stress hormone, it could vary according to stress induced while handling and also the active mating environment during peak season. It is observed that cortisol manifest the physiological activity having profound effect in the reproductive process of the fish besides secondary stressor.

References

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How to cite this article

Ningthoukhongjam Soranganba (2022). Seasonal Plasma Cortisol Level of Amur Common Carp among different Age Groups in Tarai Region of Uttarakhand. Biological Forum – An International Journal, 14(4): 464-467.