Induced Breeding and Developmental Biology of Endemic Western Ghats Fish Dawkinsia filamentosa (Valenciennes, 1844) under Captive Conditions

Abstract

In the present study, induced breeding of endemic barb, Dawkinsia filamentosa was carried out using three different synthetic hormones namely Human chorionic gonadotropin (HCG), WOVA-FH and Ovatide at different (0.3, 0.5, 0.7 and 0.9 ml/Kg) doses. All synthetic hormones showed good performance at 0.7 ml/kg body weight. Comparatively WOVA-FH showed better performance with higher number of spawned eggs (1405±5.74 nos/female) and hatching rate (90±0.6%). The study concluded that WOVA-FH at 0.7 ml/kg is an ideal for induced breeding of D. filamentosa. Fertilised eggs were golden in colour with an orange tinge. Hatching took place 34- 36 hrs (26±0.50C) of post fertilization. Yolk sac remained up to 60 hrs of post hatching. Complete developmental stages of D. filamentosa from egg to adult were recorded in captive condition. The present study aids in introducing hatchery-bred seeds of valuable indigenous fish Dawkinsia filamentosa into the ornamental fish trade. Availability of hatchery seed may reduce the wild exploitation and contributes to the conservation of the natural resources.

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

“…Hatching was observed 33-35 h after the fertilization, and WOVA-FH and percentage of fertilization and hatching rate were also greatly affected by the dose of hormone used. Rath et al (2007) et al, 1992;Islam & Chowdhury, 1976;Mahadevi et al, 2020aMahadevi et al, , 2020bSiddik et al, 2013). Egg and embryonic development was more similar to the cyprinid fish, and similar observations were reported by Mahadevi et al (2020a) and (2020b) for D. filamentosa.…”

“…Based on previous trials conducted on breeding of the other species of same genus such as D . filamentosa (Mahadevi et al, ,2020a, 2020b), WOVA‐FH hormone has shown promising results; hence, this hormone was selected to induce breed D . rohani .…”

“…The efficacy of the varied doses of WOVA‐FH was estimated by observing the fecundity, latency period, fertilization and hatching rate. Effective fecundity of each female after spawning was determined by random sampling or by taking the photograph of egg patch on tank bottom and counting (Mahadevi et al, 2020a, 2020b). The formula to calculate other parameters is as follows: …”

“…Effective fecundity of each female after spawning was determined by random sampling or by taking the photograph of egg patch on tank bottom and counting (Mahadevi et al, 2020a(Mahadevi et al, , 2020b. The formula to calculate other parameters is as follows:…”

“…Swain et al (2008) have standardized the breeding protocols for indigenous ornamental fish varieties of P. denisonii and P. filamentosus in captivity. Mahadevi et al (2020a) carried out detailed study on the effect of different synthetic hormone on gamete maturation and spawning of Dawkinsia filamentosa and found that WOVA-FH performed better compared to hCG and ovatide. Hence, wild-caught Dawkinsia species can be reproduced under captivity using the synthetic hormone (Mahadevi et al, 2020b).…”