Abstract This study was performed to determine the efficiency of various hormones on the ovulation of knife fish, Notopterus notopterus , in captivity. In total, 81 fish were grouped into nine treatments with three replicates, maintaining the sex ratio 1:2 (male to female). Brood fish in all the groups were given pituitary gland extract (PGE) 2 mg kg −1 body weight (BW) as a preliminary dose and different doses of PGE (6, 8, 10 mg kg −1 BW), human chorionic gonadotropin (3000, 4000, 5000 IU kg −1 BW), and luteinizing hormone releasing hormone‐analog (LHRH‐a) (150, 200, 250 μg kg −1 BW) plus domperidone (DOM) (15, 20, 25 mg), respectively, as the final dose. The optimal hormone combination was identified based on key spawning parameters: ovisomatic index (5.2%), fecundity (487 eggs), egg diameter (3.27 mm), fertilization rate (95.2%), embryo development time (159 h), and hatching rate (70.3%). Accordingly, the recommended hormone protocol for initiating breeding in knife fish is a priming dose of PGE (2 mg kg −1 BW) followed by LHRH‐a (200 μg kg −1 BW) combined with 20 mg DOM for optimal reproductive performance. These findings mark a pivotal step towards establishing captive breeding protocols for knife fish, offering a sustainable solution to seed scarcity while contributing to the species' aquaculture potential and conservation.
Devkota et al. (Mon,) studied this question.