Optimizing induced breeding and larval rearing of the Moustached danio (Danio dangila) in captivity: unleashing its aquaculture potential

Abstract

Danio dangila, a valuable ornamental fish native to India, has experienced notable population declines due to overexploitation, habitat degradation, and environmental fluctuations. This study evaluated its breeding performance, embryonic development, and larval rearing under captive conditions using the synthetic hormone Ovaprim™. Wild broodstock collected from the wetlands of West Bengal were maintained on a live Tubifex diet at 5% of body weight daily. Initial attempts to induce spawning through environmental manipulation were unsuccessful. Subsequently, induced breeding trials were conducted, with the best results observed in Set IV, where females received 0.4 ml kg-1 and males 0.3 ml kg-1 of Ovaprim™ via intraperitoneal injection. This treatment yielded the highest number of eggs (700.50 ± 35.2), fertilization rate (64.0 ± 1.24%), and hatching success (66.6 ± 1.2%). The incubation period ranged from 18 to 22 hours at 26-28 °C. Larval rearing over 30 days in glass aquaria recorded a maximum survival rate of 40%, with exogenous feeding initiated on day 5 post-hatch. These findings highlight the effectiveness of hormonal induction in improving captive breeding success and offer helpful tips for sustainable ornamental fish production and species management.