Thermal tolerance limit and oxygen consumption rates of Labeo gonius (Hamilton, 1822) acclimated to four different temperatures.

Abstract

An experiment was conducted to evaluate the thermal tolerance limit and oxygen consumption rates of Labeo gonius (6.23±0.19 g) fingerlings acclimated to four different temperatures (27, 30, 33 and 36 °C) for a period of 60 days. Critical thermal maxima, CTmax (40.97±0.05, 41.89±0.05, 42.69±0.04 and 43.05±0.05) and critical thermal minima, CTmin (12.72±0.04, 13.62±0.04, 13.99±0.05 and 14.39±0.021) increased significantly (p<0.05) with increasing acclimation temperatures. Similarly, Lethal thermal maxima, LTmax (41.63±0.04, 42.41±0.05, 42.99±0.02 and 43.42±0.04) and Lethal thermal minima, LTmin (12.24±0.03, 13.25±0.03, 13.68±0.05 and 13.97±0.04) increased significantly (p<0.05) with increasing acclimation temperatures. A thermal tolerance polygon over the range of 27 to 36 °C had a calculated area of 256.24 °C2. Oxygen consumption rate increased significantly (p<0.05) with increasing acclimation temperatures. Similarly, oxygen consumption rates also significantly (p<0.05) differed without acclimating at different temperatures. Temperature quotient (Q10) was found to be 1.72 for acclimated fish and 2.23 for non-acclimated fish. From this study, it is evident that thermal tolerance limit of L. gonius is comparable to Indian major carps, indicating their potential for diversifying freshwater aquaculture.