Successful breeding of the endemic cyprinid fish Dawkinsia rohani in controlled condition—First report

Abstract

The present experiment was conducted to breed a vulnerable cyprinid fish, Dawkinsia rohani (Rohan's barb), in captivity through hormonal inducement using one of the reproductive synthetic hormones WOVA-FH, since these fish did not breed spontaneously in captivity. The experiment was conducted in 500-L capacity fibre-reinforced plastic tanks with breeding hapa. The male (length 8.5 ± 1.5 cm and weight of 12 ± 2 g) and female (length 9.5 ± 2 cm and weight of 15 ± 1.5 g) brooders were injected intramuscularly with variable dose of WOVA-FH and released into the breeding hapa at 2:1 (male:female) ratio. Varied doses of WOVA-FH used for fish in the present study refer to 0.3 ml/kg (T1), 0.5 ml/kg (T2), 0.7 ml/kg (T3), 1.0 ml/kg (T4) and 0.0 ml/kg T0 (control). General courtship behaviour was observed in hormone-induced fish after 6–9 h after injection. Breeding was observed in all the treatment group fish except T0 (control groups). Success of spawning, fertilization and hatching rate varied depending on the dose of hormone. Significantly higher fecundity (1142.3 ± 40.20 eggs/female), fertilization rate (90.2 ± 0.67%) and hatching rate (88.92 ± 0.25%) were achieved in fish injected with 0.7 ml/kg for female and 0.3 ml/kg for male per kg body weight compared to other hormone treatment groups. Dosage levels influence the percentage of spawning, egg stripping, fertilization and hatching rate. The present study successfully standardized the dose for induced breeding of D. rohani. The standardized breeding technology will be helpful in breeding, conservation and propagation of the endemic indigenous ornamental fish, D. rohani.