Effect of short term infection of Paradactylogyrus catlaius on selected haematological and non-specific immune parameters in Catla catla (Hamilton, 1822)

Abstract

A short term (20 days) cohabitation infection study of the gill fluke Paradactylogyrus catlaius infecting Catla catla was conducted to investigate on the mode, intensity and effect of infection on selected haematological, immunological and serum biochemical parameters in the infected fish. The results revealed that the increase in the number of parasites is rampant and increased to 161±23 parasites per gill lamella in just 20 days post-challenge. Further, significant decrease (p≤0.05) in haemoglobin (Hb), total erythrocyte count (TEC), lysozyme activity, bactericidal activity, total protein and albumin content was noticed whereas a significant increase in total leucocyte count (TLC) was recorded. Globulin content and superoxide anion production increased significantly initially and then decreased (p≤0.05). From this study, it was found that P. catlaius infection causes no mortality in catla till the 20th day of challenge but the infection can spread to the whole population of catla in short time. Further, it was also observed that the infection can adversely affect the physiological and immunological status of the infected fish. Therefore, appropriate management and control strategies need to be formulated to prevent its spread and to avoid production loss.