Growth performance and hematological parameters of pacu (Piaractus mesopotamicus) juveniles in different concentrations of total suspended solids in the BFT system

Biofloc technology (BFT) is a widely available system for aquaculture production, reducing water, and artificial diet consumption. This study evaluated the survival, growth performance, and hematological parameters of pacu juveniles subjected to different total suspended solids (TSS) concentrations of the BFT system. Juveniles were exposed to five TSS concentrations: 0, 250, 500, 750, and 1000 mg L-1 (or control, BFT250, BFT500, BFT750, and BFT1000) for 30 days. The experimental design was randomized in five treatments and three replicates (9 fish per tank). Except for TSS and settleable solids, the water quality variables did not differ between treatments. The survival rate was 100%, and the weight gain was higher in the control group, followed by BFT1000. The hepatosomatic index was significantly lower in the control group compared to the BFT1000. Generally, the highest blood glucose and pH levels were found in BFT500 and BFT750, respectively. The treatments with TSS showed hematological changes (hematocrit, hemoglobin, and hematimetric indices), with the highest changes occurring in juveniles exposed to values above 500 mg L-1 TSS. In conclusion, although the treatments with TSS can reduce growth, increase HSI, and cause hematological changes, it is a promising alternative for producing pacu juveniles, mainly BFT1000.