Effect of temperature on growth performance and immuno-biochemical changes in endangered golden mahseer, Tor putitora (Hamilton, 1923)

The present study to evaluated the effect of different thermal regimes on growth performance, oxidative stress, antioxidant enzymes, and immuno-biochemical responses of endangered golden mahseer, Tor putitora. A total of 144 healthy fingerlings were randomly distributed into four experimental groups (13 °C, 16 °C, 19 °C, 22 ± 0.5 °C) in triplicate rectangular fiberglass reinforced plastics tanks. The highest and lowest Growth rate, Specific growth rate, Daily growth index, Thermal growth coefficient, Viscera-somatic index, and Growth hormone were observed at 19 °C and 13 °C, respectively. The lowest SGR and VSI were observed at 22 °C. The feed conversion ratio was significantly higher in the control group (p < 0.05), whereas there was a significant decrease in all the treatment groups. The highest and lowest hepato-somatic index was observed at a temperature of 13 °C and 16 °C, respectively, while no significant (p > 0.05) impact of temperature regimes were observed on the length-weight relationship. Regarding hematological indices results, the hematocrit, hemoglobin, total erythrocyte count, and total leucocyte count were significantly higher at 13 °C, whereas the lowest was observed in all the treatment groups (p < 0.05). Higher myeloperoxidase activity and lysozyme activity were observed at 13 °C, whereas lowest at 22 °C. Anti-oxidant potential, SOD, and catalase (muscle) were significantly higher in the control group, whereas they gradually decreased with an increasing temperature. Catalase (liver) level was significantly higher at 22 °C. GST content was significantly higher at 22 °C compared to 13 °C, and GST content increased gradually with an increased temperature. The lipid peroxidation level in the liver and muscle was significantly higher at 22 °C and 13 °C, respectively. The present study concluded that the different phenotypic, antioxidative, and immuno-biochemical modulations of golden mahseer fingerlings in response to different temperature regimes could be used for better management and propagation.