Thermal tolerance and oxygen consumption of Indian Major Carps acclimated to four temperatures

Abstract

Critical thermal maxima (CTMax), critical thermal minima (CTMin), lethal temperature maxima (LTMax) and lethal temperature minima (LTMin) were determined in Indian Major Carps (Labeo rohita, Catla catla and Cirrhinus mrigala) acclimated to 26 C, 31 C, 33 C and 36 C for 30 days. At each acclimation temperatures, CTMax, CTMin were 40.63, 41.91, 42.65, 42.86 and 13.73, 14.2, 15, 15.58 (L. rohita), 40.45, 41.39, 42.63, 42.73 and 13.92, 14.4, 15.2, 15.63 (C. catla), 42.25, 42.55, 42.76, 43.07 and 12.12, 13.7, 13.81, 13.95 (C. mrigala), respectively. Similarly, LTMaxand LTMin at 26 C, 31 C, 33 C and 36 C were 41.16, 42.3, 43.06, 43.31 and 13.31, 14.71, 14.43, 14.9 (L. rohita), 41.03, 41.7, 42.96, 43.06 and 13.6, 13.95, 14.81, 14.98 (C. catla), 42.51, 42.93, 43.11, 43.68 and 11.9, 13.3, 13.45, 13.56 (C. mrigala), respectively. Rate of oxygen consumption with and without acclimation were determined at 26 C, 31 C, 33 C and 36 C and were significantly ðpo0:05Þ different. Final preferred temperature in Indian Major Carps was estimated through Q10 to be between 31 C and 33 C. Thermal tolerance polygon values over entire range of tolerance region (12–40 C were 744.8 C2 in L. rohita, 728.8 C2 in C. catla and 801.8 C2 in C. mrigala, respectively.