Vol. 11, Special Issue 10 (2022)

Author(s):
Ningthoukhongjam Soranganba

Abstract:
Fish reproduction is a synchronous of physiological elements along with environmental factors influenced by seasonal changes, and both this factors plays a key role in triggering the hormonal secretion leading to successful production of offspring’s. A study on the estradiol (E2) level from gonads and plasma samples of two different age groups (1+ and 2+ years) of amur common carp for both male and female was conducted seasonally (spring, summer, autumn and winter) using RP-HPLC method. The study showed that both the age groups have similar seasonal pattern in gonadal and plasma E2 levels, with spring season showing highest level followed by summer and autumn respectively. A slight increase in E2 level was observed post autumn i.e. winter season. As compared to male counterpart, the peak gonadal E2 levels were observed during spring as 6.75±0.02 ng/mg and 4.69±0.09ng/mg for 2+ and 1+ old respectively. Similarly the peak plasma E2 levels of 7.55±0.01 ng/mg and 4.17±0.03ng/mg were recorded for 2+ and 1+ old during peak spring season respectively. Gonadal and plasma E2 showed significant differences (p<0.05) in relation to age, seasons and interaction (age & seasons) in both age groups. Using Pearson’s correlations (p<0.01) significant positive results were observed between GSI with gonadal and plasma E2. The present study indicates the role of E2 and seasonal influences in regulating hormonal changes thus effecting reproductive success of Amur common carp, Cyprinus carpio haematopterus, during peak seasons of spring followed by summer and age factor playing a key role in reproduction. Therefore, fully matured 2 years and above age amur common carp are more feasible for breeding programme and spring season will be the most conducive season for reproduction.