Amelioration of water quality and physiological performance of GIFT fish through the incorporation of Lemna minor and Lamellidens marginalis for ecological bioremediation in freshwater integrated multi-trophic aquaculture system.

The study extended over 60 days to assess the impact of extractive species on improving water quality and enhancing GIFT fish production performance within the FIMTA system. Prior to initiating the experiment, the extraction capacities of both organic and inorganic extractives were assessed. Subsequently, based on these evaluations, GIFT fish were co-cultured with freshwater mussels and aquatic macrophytes as organic and inorganic extractive agents, respectively, within 1000 L FRP tanks. Three treatment combinations were established: GIFT fish with Lemna minor (T1), GIFT fish with Lamellidens marginalis (T2), and GIFT fish with both L. minor and L. marginalis (T3). The control treatment (C) consisted solely of GIFT fish. GIFT fish were stocked at a density of 40 m−2, while L. marginalis at 250 g per tank and L. minor covering 25% of the tank surface. GIFT fish were fed with floating commercial pelleted feed at 4% of body weight (30% CP). The results indicated that among the water quality parameters, chlorophyll a, dissolved solids, and suspended solids showed a reduction in T3. The control group exhibited elevated levels of BOD and COD, whereas the treatment groups showed significantly lower levels. Furthermore, the control group demonstrated increased conductivity levels, while T3 exhibited the lowest levels. In T3, a significant reduction was observed in both POM and POC. Growth variables like SGR and PWG were found to be highest in T3. Regarding enzyme activity, the control group exhibited lower levels of protease, lipase, and amylase, while the highest levels were observed in T3. Physiological enzyme activities such as LDH, MDH, ALP, and ACP were significantly increased (p < 0.05) in the control system, indicating elevated water pollution levels. Meanwhile, bacterial load was found to be very low in the FIMTA system (T3). These findings suggest that the integration of GIFT with L. minor and L. marginalis in the FIMTA system has the potential to enhance water quality and physiological responses, ultimately contributing to higher yields. [ABSTRACT FROM AUTHOR]