This study evaluated the zootechnical performance of four rainbow trout strains (wild, blue, yellow-albino, and white-albino), considering water quality and growth parameters at different stages. The fish were distributed in 2 m³ circular tanks in an open system with constant flow, in triplicate (12 tanks). They were fed ad libitum 3 times a day and monitored for weight, feed conversion at 0, 60, 120, 180, and 270 days. Environmental conditions remained within the ideal standards for the species, with average values of dissolved oxygen (6.84 ± 0.03 mg/L), pH (6.4 ± 0.02), and temperature (maximum 15.6 ± 1.56°C and minimum 13.5 ± 1.89°C). After a 24-hour fast, 60 fish (20 per tank) were weighed in each period. The experiment followed the ethical guidelines of the Fisheries Institute (CEUA-IP 003/2022). ANOVA and Tukey’s test (5%) were performed. There were significant variations between the rainbow trout strains (Table 1). The wild strain performed better at the beginning of the experiment (p<0.05), while the yellow strain weighed more at the end, reaching 301.70g (p<0.05). In contrast, the white-albino strain showed the lowest weight gains and the highest feed intake at all stages, demonstrating lower production efficiency. The yellow-albino strain performed better. The white-albino strain yielded poorly, suggesting genetic influence and it needs further studies.
Financial support was given by FAPESP 2022/08044-6.