Oral Administration of GnRH and Domperidone via Gel Feed and Their Effect on Reproductive Performance of (Bengal Danio), an Ornamental Fish.

This study investigated the effects of dietary Gonadotropin-releasing hormone (GnRH) and domperidone on the reproductive performance of during a 40-day trial. Five treatment groups received varying doses of GnRH (100, 50, 25, 12.5 µg/kg body weight) in combination with domperidone (50, 25, 12.5, 6.25 mg/kg body weight), embossed in a gel-based diet alongside a control group without the exogenous hormones. Reproductive performance was examined by measuring the gonadosomatic index, fecundity, reproductive hormone levels, and histological features of the gonads, blood parameters, and antioxidant enzyme activity. The T1 group (100 µg GnRH + 50 mg domperidone) exhibited the highest GSI in both sexes. The histological analysis of testes from T1, T2 (50 µg GnRH + 25 mg domperidone), and T3 (25 µg GnRH + 12.5 mg domperidone) groups revealed an increased presence of late-stage spermatids and spermatozoa. In females, the T2 group produced the highest proportion of advanced-stage oocytes and demonstrated the greatest absolute fecundity (1300 ± 23 eggs). However, the control group showed the highest fertilization and hatching rates. Testosterone levels were significantly elevated in the T3 group, while vitellogenin levels increased in the T1 and T2 groups. Antioxidant enzyme activity varied, with the T1 group displaying higher superoxide dismutase activity in gills and liver, and the T2 group showing increased SOD activity in muscle and brain. Improvements in haematological parameters were observed across all treatments. These results suggest that an optimal dose of 50 µg GnRH + 25 mg domperidone can enhance reproductive performance in .