The genus Horabagrus (Siluriformes: Horabagridae), endemic to the west-flowing rivers of India’s Western Ghats, represents a distinct and conservation-relevant catfish lineage. The recent discovery of the cryptic, range-restricted H. obscurus from the Chalakkudy River expands the genus beyond H. brachysoma and the endangered H. nigricollaris, highlighting the region’s freshwater biodiversity. As the largest species in the genus (~2 kg) and a minor fishery resource, H. obscurus has been prioritised for conservation and sustainable management. We report the first successful captive breeding, larval rearing, and restocking programme for this species. Brooders induced with WOVA-FH (1 ml kg⁻¹ body weight) ovulated within 12–13 h. Golden-yellow eggs (1.8–2.1 mm) showed fecundity of 200–230 eggs g⁻¹ ovary and 80–90 % fertilisation success. Hatching occurred within 28–30 h, and yolk-sac absorption was complete by 72 h post-hatch, initiating exogenous feeding. Under optimised rearing conditions (26–28 °C, pH 6.8–7.4), hatching exceeded 90 % and larval survival surpassed 95 %, confirming high seed production potential. Hatchery-reared juveniles were released in their native stretch between Athirapilly and Thumburmuzhy, providing a practical model for population recovery. This study delivers the first comprehensive reproductive profile and standardised seed production protocol for H. obscurus, offering a scalable approach for its ex-situ conservation, ranching, and future aquaculture prospects.