Effect of water salinity on total protein and electrophoretic pattern of serum proteins of grass carp, Ctenopharyngodon idella.

In this study the effects of water salinity on serum total protein and its components in grass carp were investigated. The aim of this study was to determine the effect of salinity tolerance of fish on total serum protein level and its components as an indicator of liver and kidney activity. One hundred and twenty grass carp were divided into four groups, randomly. The first three groups were reared in concentration of 4, 8 and 12 g L(-1) of salt solution, respectively, and the fourth group was reared in freshwater and served as control. After 3 weeks, blood samples were collected and after harvesting the blood serum, serum total protein and protein components were measured with Biuret and electrophoresis methods, respectively. Results showed that mean value of serum total protein in the control and three salinities groups were 2.75, 3.28, 2.90 and 3.13 g dL(-1), respectively. Five fractions of serum protein were electrophoretically observed as: albumin (Alb), alpha-1 globulin (α1-glu), alpha-2 globulin (α2-glu), beta globulin (β-glu) and gamma globulin (γ-glu). There were not any significant differences between the average mean of serum total protein of experimental and control groups (p > 0.05). However, Alb, α1-glu and β-glu levels in the experimental groups were significantly higher than in the control group (p < 0.05). The average of α2-glu and γ-glu revealed no significant difference between the experimental groups (p > 0.05). In conclusion, our results showed that increasing water salinity could have a significant effect on Alb, α1-glu and β-glu levels but not on total serum protein in grass carp.