Seasonal modulation of reproductive hormones and related biomarkers in coldwater cyprinid Barilius bendelisis (Hamilton, 1807)

AbstractBarilius bendelisis is a valuable ornamental and food fish from India in which the endocrine control of its reproduction activity has not been widely reported. The present study was aimed to elucidate changes in serum endocrine hormones: 17 β-estradiol (E2), testosterone (T), progesterone (P4), 17 α, 20β-dihydroxyprogesterone (17α, 20β-P), cortisol (C), triiodothyronine (T3), and thyroxine (T4); aromatase activity (ARO), vitellogenin (VTG), and total antioxidant capacity (TAC) during different seasons of the year 2014. All studied parameters showed marked seasonal variations. The highest E2 level in males and females were recorded in winter (January) and rainy (September) seasons respectively. The T level exhibited dual peaks in both sexes, and the highest values were observed during the winter (January) and rainy (September) seasons. The serum levels of P4 and 17 α, 20β-P during spring (March) and rainy (September) seasons were significantly higher and found associated with final sperm and oocyte maturation. The serum levels of ARO and VTG also showed bimodal pattern during the spring (March) and rainy (September) season and were well correlated with T and E2. Serum C level was detectable throughout the year in both sexes which were related to glucose metabolism and spawning events. Fluctuations in T3 and T4 levels were associated with somatic growth and reproduction events during different seasons inB. bendelisis. Serum TAC level was highest during summer (Ma...
Source: Comparative Clinical Pathology - Category: Pathology Source Type: research