Biochemical and stress responses of rohu Labeo rohita and mrigal Cirrhinus mrigala in relation to acclimation temperatures
The biochemical and stress responses of two Indian major carps, rohu Labeo rohita and mrigal Cirrhinus mrigala were studied after acclimating them to four preset temperatures (26, 31, 33 and 36° C) for 30 days. The blood glucose and liver glycogen levels showed an inverse trend in both the species and were significantly different in L. rohita at higher temperatures. The decrease in the liver glycogen level of C. mrigala, however, was not significant. Plasma cortisol levels increased significantly whereas the ascorbic acid content in the brain and kidney of both the species decreased significantly with increasing temperatures. Total lipid content in the liver of both the species decreased significantly with increasing acclimation temperatures. The phospholipid concentration decreased in L. rohita with increasing acclimation temperatures, and in C. mrigala the values decreased up to 33° C and increased at 36° C. In C. mrigala, the cholesterol level decreased up to 33° C and then increased at 36° C, but the absolute value was lower in comparison to L. rohita. The cholesterol levels, however, were not significantly different in L. rohita. Triglycerides and free fatty acids concentrations decreased significantly with increasing acclimation temperatures in both the species. The present study indicates species-specific metabolic responses of L. rohita and C. mrigala to thermal acclimation.
Document Type: Regular Paper
Division of Fish Nutrition and Biochemistry, Central Institute of Fisheries Education, Versova, Mumbai 400061, India
Department of Zoology, Vidyasagar University, West Bengal 721102, India
Molecular Biology Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India
Laboratory of Aquaculture and Artemia Reference Centre, Department of Animal Production, Ghent University, Gent 9000, Belgium
Publication date: May 1, 2009