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

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 26degreesC, 31degreesC, 33degreesC and 36degreesC 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, LTMax and LTMin at 26degreesC, 31degreesC, 33degreesC and 36degreesC 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 26degreesC, 31degreesC, 33degreesC and 36degreesC and were significantly (p<0.05) different. Final preferred temperature in Indian Major Carps was estimated through Q(10) to be between 31degreesC and 33degreesC. Thermal tolerance polygon values over entire range of tolerance region (12-40degreesC were 744.8degreesC(2) in L. rohita, 728.8degreesC(2) in C catla and 801.8degreesC(2) in C. mrigala, respectively. (C) 2004 Elsevier Ltd. All rights reserved.