Journal of Scientific Research and Reports

A 140-day experiment was conducted to identify the most effective species combination of indigenous carps (Catla catla, Labeo rohita) and exotic carps (Cyprinus carpio, Ctenopharyngodon idella) integrated with cucumber plant (Cucumis sativus) cultivation in an aquaponic system. Experimental design included three treatments with respective control, each replicated three times. The fish species compositions for the treatments were: Labeo rohita + Catla catla (T1), Labeo rohita + Cyprinus carpio (T2), and Ctenopharyngodon idella + Cyprinus carpio (T3), maintained at a 70:30 ratio with a stocking density of 2000 g/m³, and cucumber plantlets integrated at a density of 12 plants/m². Controls for each treatment had the same fish composition but were not integrated with plants. During experimental period, fish were fed at 4% of their body weight. Water quality parameters, including temperature, dissolved oxygen (DO), and pH, were monitored daily, while total hardness, alkalinity, ammonia, nitrite, and nitrate were measured at 20-day intervals. Although the concentrations of ammonia, nitrite, and nitrate were slightly higher in the control groups than in the treatments, and DO levels showed an opposite trend, the differences were not statistically significant, and all values remained within optimal ranges. Fish growth parameters, including weight gain, percentage weight gain, specific growth rate (SGR), daily weight gain, feed efficiency ratio (FER), and protein efficiency ratio (PER), were evaluated. The results showed that the highest individual weight gain was observed in Catla catla in T1 (89.76±0.20 g), followed by Cyprinus carpio in T3 (85.43±0.06 g), and Ctenopharyngodon idella in T3 (81.76±0.41 g), with the lowest observed in Labeo rohita in T2 (66.03±0.29 g). Overall, the highest combined body weight gain was recorded in T3, followed by T1 and T2, respectively. Plant performance parameters, including height gain (cm), percentage height gain, growth rate (cm/day), and fruit yield (kg/m²), were also measured, with no significant differences observed between treatments and controls. Among the treatments, the highest cucumber fruit yield was obtained in T3 (2580±19.3 g), followed by T1 (1782.4±14.6 g) and T2 (1082.2±15.4 g). Further research is recommended to explore higher stocking densities for both fish and plants to enhance productivity and profitability in this intensive aquaponic system while ensuring sustainability.