Impact of photoperiod and temperature on melatonin, growth hormone, estradiol, and vitellogenin levels in female African catfish (Clarias gariepinus) reproduction cycle

Abstract

This study aimed to investigate the hormone levels of melatonin (Mel), estradiol (E2), vitellogenin (VTG), and growth hormone (GH) in inducing reproduction cycles in female African catfish, Clarias gariepinus, to develop actionable strategies that directly contribute to the efficiency and sustainability of African catfish farming. The treatments involved in this study are three photoperiod variations (L8:D16, L4:D20, and L0:D24) combined with two different temperatures (28 °C and 32 °C) during 90 days of culture (doc). Serum hormone levels were measured using ELISA, and egg diameter was measured using a microscope every 30 days. The results showed that the biological rhythm of the reproductive cycle of African catfish was accelerated by constant exposure to a photoperiod of L0:D24 and 28 °C for 30 days. In this condition, the levels of hormones involved in the reproductive such as Mel (89.82 ± 5.49 ng/mL), E2 (1.66 ± 0.02 ng/mL), VTG (100.96 ± 0.27 ng/mL) and GH (0.33 ± 0.02 ng/mL) with an average egg diameter of 1.15 ± 0.07 mm. These results highlight the complex interplay between photoperiod, temperature, and reproductive physiology in African catfish, suggesting that environmental manipulation could be a valuable tool for optimizing breeding conditions in aquaculture. The conclusion of this study is that manipulating the photoperiod and temperature is an effective and economical approach to stimulate fish spawning. These findings have important implications for African catfish breeding practices, as they provide a clear and actionable strategy for improving reproductive performance.