Water Quality and Growth Responses of Catfish, Leather Carp, and Goldfish in an Indoor Aquaponics System Integrated with Apple Mint

Abstract

Aquaponics integrates fish culture with hydroponic plant production, enabling a sustainable approach to food production through nutrient recycling. This study evaluated the growth performance of three freshwater fish species—catfish (Silurus asotus; T1), leather carp (Cyprinus carpio nudus; T2), and goldfish (Carassius auratus; T3)—reared in an indoor aquaponics system with three replications over 50 days and assessed their effects on water quality and apple mint (Mentha suaveolens) production. Water quality, fish, and plant growth parameters were monitored throughout the study. T1 exhibited significantly greater fish and plant growth performance than T2 and T3 (p < 0.05), thereby increasing nutrient input into the culture water. In contrast, T2 and T3 exhibited lower fish growth but higher survival rates. Significant differences in fish proximate composition were observed among treatments (p < 0.05). T3 exhibited higher moisture and crude lipid contents, whereas T1 and T2 showed higher crude protein contents. Water quality and mineral concentrations remained within acceptable aquaponic ranges. Species-specific differences influenced nutrient accumulation and system dynamics, demonstrating that fish species selection strongly influences both fish productivity and plant performance. The catfish–apple mint combination showed the highest potential for nutrient recycling and biomass production under controlled conditions, but long-term sustainability may depend on optimizing catfish management to mitigate mortality.