Precocious ovarian recrudescence and induced off–season spawning of Heteropneustes fossilis by D-Lys6 salmon gonadotropin releasing hormone analog (sGnRH-A)

The feasibility of photothermal treatment and use of salmon gonadotropin releasing hormone analogue (sGnRH-A) for induced spawning of Heteropneustes fossilis outside the spawning season was investigated. Fish were maintained at 30° C and 14 h light (L)/10 h dark (D) for 60 days between the post-spawning season and preparatory season. Fish attained gonadal maturity 4 months earlier compared to the natural spawning season. Mature fish were induced to spawn by D-Lys⁶ sGnRH-A at a dose of 25 μg kg^?1 body weight. The eggs obtained were fertilizable. Injection of D-Lys⁶ sGnRH-A at different time points during the photodiurnal cycle did not influence the latency period and spawning of H. fossilis .