Comparisons of Physiological Responses of Tilapia (＂Oreochromis mossambicus＂) and Grass Carp (＂Ctenopharyngodon idella＂) under Acute Cold Stress

Li-Han Chen ； Ting-Chun Weng ； Jou-Chun Chou ； Paulus S. Wang

《Adaptive Medicine》 7卷3期 (2015/09) Pp. 141-145

https://doi.org/10.4247/AM.2015.ABF119

並列摘要

Cold shock causes great economic losses in tilapia aquaculture in the world. Tilapia is one of the major farmed fishes with less cold tolerance than grass carp, another important commercial teleost. Since cold tolerance is highly related to physiological responses under cold shock, to compare the cold response in physiology could improve cold injury losses in tilapia aquaculture industry. In the present study, 14 and 23 blood samples were collected at 28℃ from grass carps and tilapias, respectively. Then fish were moved to and stay in a cold room with 13℃. Nine and nineteen blood samples of each the teleost species were collected one day after moving. All the blood samples were measured for osmolality. Concentrations of plasma sodium, potassium, calcium, and glucose were also measured, respectively. Hematocrit, blood viscosity, and plasma viscosity were also measured in the study. For both grass carp and tilapia, the osmolality and concentration of the plasma sodium decreased from at 28℃ to at 13℃, while plasma glucose level and plasma viscosity increased. Concentration of potassium and blood viscosity raised in tilapias but did not change in grass carps. Cold exposure also influenced hematocrit in grass carps but did not affect hematocrit in tilapias and calcium levels in both grass carps and tilapias. These results suggest that less cold tolerance of tilapia may be due to increased plasma potassium, unchanged hematocrit, and induced blood viscosity.

並列關鍵字

blood viscosity ； cold shock ； grass carp ； hematocrit ； potassium level ； tilapia