Spawning performance of native threatened spotted snakehead fish, Channa punctatus (Actinopterygii: Channidae: Perciformes), induced with Ovatide

Abstract

Background. The spotted snakehead, Channa punctatus is a highly priced freshwater food fish species in India. The culture of snakeheads is still not common due to the scarcity of quality seed supply and lack of knowledge on their feeding and breeding techniques. Therefore an experiment was conducted to test the efficacy of a new spawning agent, Ovatide in stimulating ovulation of snakehead fish under a controlled captive condition. Materials and methods. In total, 12 matured females and 24 male fish weighing 50&#8211;90 g were randomly selected for three hormonal treatment groups and one control group. Both male and female fish in each treatment group were administered with either saline (0.9% NaCl, control group), or 0.2, 0.4, and 0.6 mL of Ovatide per kg of body weight (BW), respectively. Each breeding set consisted of two males and one female. The hormone-treated fish were then held in concrete tanks for spawning. The breeding performance was evaluated based on spawning fecundity, spawning response, percentage fertilization, and percentage hatching. Results. No spawning behaviour or performance was observed in control group. Partial spawning was observed with the Ovatide dose of 0.2 mL &#183; kg-1 BW, and complete spawning was noticed in the medium Ovatide dose (0.4 mL &#183; kg-1 BW), and the higher dose (0.6 mL &#183; kg-1 BW) administered fish. The highest total spawning fecundity (P < 0.05) was recorded when the females were injected with 0.4 mL of Ovatide &#183; kg-1 BW than those injected with other doses. The latency period and the number of spawned eggs were ranged from 25 to 31 h and from 1080 to 5814, respectively. The highest fertilization- (90.6%) and hatching (91.33%) rates were also observed at the medium dose (P < 0.05). With regard to hatching rates, no significant difference was noticed between the medium- and higher doses of Ovatide-treated groups. Conclusion. The synthetic gonadotropin-releasing hormone with a dopamine antagonist at the dose of 0.4 mL &#183; kg-1 BW could be used as an appropriate stimulating agent for successful spawning and induced breeding of C. punctatus under captive conditions.

Keywords

• Snakehead
• Channa punctatus
• hormones
• induced spa