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¹ ICAR Research Complex for North Eastern Hill Region, Barapani, 793 103, Meghalaya, India
² ICAR Research Complex for Eastern Region, P.O.,B.V.College, Patna, 800 014, Bihar, India DOI : 10.4194/1303-2712-v13_2_19 Viewed : 4315 - Downloaded : 3274 In this study, we determine critical (CTMax) and lethal (LTMax) thermal tolerance, acclimation response ration (ARR), rate of oxygen consumption and stress in two potential ornamental fishes of the North Eastern Hill region of India, Danio dangila and Brachydanio rerio. The fishes were collected from wild and acclimatized at 18°C for 30 days. The fishes were then constantly reared at temperature regime of 20, 25, 30 and 35°C separately in insulated plastic tank for 45 days. Fishes from each rearing temperature were subjected to constant rate of increase at 1.0°C/min to determine the thermal tolerance. The results implicate significant increase (p<0.05) in CTMax (36.2±0.02, 37.7±0.31, 39.6±0.07, 40.9±0.10) and LTMax (38.1±0.08, 39.8±0.06, 40.0±0.07, 41.1±0.04) in D. dangila with increasing acclimation temperatures of 20, 25, 30 and 35°C, respectively. Similarly, CTMax (36.4±0.05, 37.2±0.04, 38.7±0.03, 39.8±0.01) and LTMax (39.8±0.03, 40.4±0.02, 41.2±0.06, 42.2±0.03) increased significantly (p<0.05) in B. rerio with increasing acclimation temperatures. Inter species variation was evident between the temperatures. Oxygen consumption rate increased (p<0.05) with increasing temperature in both the species. Overall, our results suggest that B. rerio is more thermal tolerant and show better adaptation in comparison to D. dangila. Keywords : Thermal tolerance, oxygen consumption, Danio dangila, Brachydanio rerio, global warming