Study of Bottom Substrate Variation in Zero Water Discharge Aquaculture for Mahseer Fish Tor soro Nursery

Mahseer fish Tor soro, an endemic species in Indonesia, is currently declining its population due to the overreliance on wild captures to meet consumption demands. Furthermore, the survival rate of fry is alarmingly low, necessitating the implementation of sustainable fry cultivation initiatives to bolster the demand for Mahseer fish. Environmentally friendly aquaculture practices, particularly those employing the zero-water discharge principle, offer a promising solution for establishing Mahseer fish nurseries. In cultivation methods, adding bottom substrates to resemble the natural habitat of Mahseer fish can enhance their physical performance and improve fish welfare. This study aimed to evaluate the effects of different substrates on the nursery of Mahseer fish, specifically utilizing (A) coral rock, (B) limestone, (C) crushed stone, and (D) no substrate (control) as treatments. The results demonstrated that the use of substrate media in the cultivation tanks positively influenced water quality, stress levels, and production performance of Mahseer fish. Among the treatments, the utilization of coral rock (A) as a substrate medium yielded the best results in terms of water quality, stress response, and production performance throughout the study compared to the other treatments.