Influence of biometric characteristics and gender on serum IgM in the Benni, Barbus sharpeyi Gunther, 1874 (Osteichthyes: Cyprinidae)

IgM is the only known immunoglobulin in fishes with an important role in immune responses. This study was done to evaluate serum IgM level in Barbus sharpeyi and to study the influence of weight, length and sex on it. IgM value was determined in the serum of 42 male and female B. sharpeyi (Benni) fish using RIA method. Fish came from Dashte azadegan fish farm at the southwest of Iran. The mean value of IgM was 62.8 mg/dl (42 and 78.4 mg/dl in males and females, respectively). There was a significant difference between males and females IgM level (p<0.05). Serum IgM value was also compared in fishes with different weight and length and the results showed that serum IgM increases with increasing fish weight (p<0.05). The correlation coefficient between the serum IgM concentration and morphometric features of B. sharpeyi indicated that fish weight, length and sex have influence on serum IgM.