The experiment was carried out for 56 days using 160 fingerlings. The temperature of four randomly selected recirculation systems was regulated, two of them at 27°C and two at 22°C. Weighings were carried out every 15 days to evaluate weight gains (GPT), thermal growth coefficient (CTC), specific growth rate (TEC), initial and final K condition factor (FK) (Table 1), rate of feed conversion (FCR) and protein efficiency rate (PER). At the end of the trial, the viscerosomatic indices (VIS) and head-body ratio (C/C) were obtained, and mortality was also recorded.
Significant differences (p<0.05) were observed between treatments in all parameters (GTP, CTC, TEC, FCR, PER, IVS, and C/C) except mortality and the condition factor. The stimulation of the metabolic rate was evident in fry developed at higher temperatures (Figure 1), which resulted in weight gains up to four times greater for fish developed at 27°C (2.72 ± 0.19) than those at 22°C (0.54 g ± 0.05).