Induced Spawning of Grass Carp Ctenopharyngodon idella, Using Common Carp Pituitary Extract with Domperidone

To test the efficacy of the technique of using dopamine antagonists with pituitary extracts, experiments were conducted in July, 2022, at Masab Al Sen (Al Sen estuary) Fish Farm and Hatchery, General Commission for Fisheries Resources, Syria. In all, 18 sets (2 female x 4 male in each set) were tried individually. 9 sets were treated with domperidone (DOM) and carp pituitary extract (CPE) and they constituted the experimental sets, while the rest 9 were treated with CPE and formed the control sets. The ovulation ratio, absolute fecundity, relative fecundity (number of eggs/kg), fertilization rate and hatching rate was 92.85%, 384645 ± 70990 eggs, 56853.22 ± 5385.68 eggs/kg, 80.02% and 61.54%, respectively in the experimental sets whereas it was 92.85%, 355172 ± 53008 eggs, 52059.73 ± 3853.71 eggs/kg, 72.50% and 54.46% respectively in case of control sets. Hatching occurred within 20 h and 45 min to 21 h after fertilization in the experimental sets whereas it was 20 h and 45min to 21 h and 20 min in case of control sets at 26-26.5°C. It was observed that body weight has positive influence on absolute fecundity (r = 0.98, 0.99) and relative fecundity (0.97,0.97) in case of experimental sets and control sets respectively.