Effects of Synthetic Hormones on Fertilization, Fecundity, Hatching and Gonado-Somatic Index of Giant Snakehead (Channa Marulius) in Captivity

Abstract

The effects of a crude protein (40% CP) diet on the spawning performance of giant Snakehead (Channa marulius) broodstock were assessed in this study through a three-week feeding trial. Mature C. marulius brood stock (N = 36) was taken from the brooders pond and stocked into nine small experimental breeding ponds, each measuring 4mx2mx1.5m (LxWxD). Following acclimatization, all male and female C. marulius broodstock with an average weight of 1.5–2.5 kg BW and a length of 70 cm were removed from the small breeding ponds. The current study's objective was to induce breeding in C. marulius by injecting synthetic hormones intramuscularly and monitoring fertilization, fecundity, hatching, and gonado-somatic index. Using a completely randomized design (CRD), nine fishponds were split into three treatments (T₁, T₂, and T₃) during the study period, each with three replicates. In addition to evaluating the effects of artificially applied hormones, Conceptal® (T₁), Suprefact® (T₂), and Ovaprim® (T₃), this study aimed to comprehend the reproductive biology of C. marulius. The hormones were injected into the test fish at the following proportion (0.3ml, 0.4ml and 0.5ml to male and 0.8ml, 0.9ml and 1.0ml to female’s ml/kg body weight) and then released into the earthen ponds for large scale production of seed. Two-way analysis of variance (ANOVA) was used. The results showed no successful spawning on Conceptal®. The gonado-somatic index (GSI) estimates for the study period showed that Suprefact had the highest average GSI values for both males and females (3.32±1.62% and 1.67±0.18%, respectively), followed by Ovaprim (1.13±0.56 and 1.22±0.68, respectively). Absolute fecundity was also estimated. The result showed that fish stimulated with suprefact (T₂) obtained the highest average fecundity (3079.3±100.7%), fertilization rate (96.33±1.20%), hatching rate (94.67±2.40%), and survival rate (95.75±1.51%), then in ovaprim fecundity rate (1669.3±836.5%), fertilization rate (58.00±29.02), hatching rate (61.27±30.65), survival rate (64.67±32.34%), respectively. In conclusion, the use of Suprefact® and Ovaprim® can optimise the results of C. marulius breeding induction in small experimental breeding ponds, ensuring higher-quality eggs and a greater number of normal larvae.