Study of changes of some hematological factors of Barbus luteus and its comparison with fishes infected by larval stage of Contracaecum sp.

In order to study the haematological factors of Barbus luteus of Parishan lake and its comparison with fishes infected by larval stage of Contracaecum sp. Sixty fish consisting of 30 healthy and 30 infected by the parasite were caught from the Parishan lake and studied. After blood sampling, autopsy of fishes were performed based on seeking parasitical infection of abdominal cavity to larval stage of Contracaecum sp. Then haematological tests were performed including differential counting of white blood cells, measuring Haematocrit (PCV) and total counting of red blood cells and white blood cells. The result in both groups showed that lymphocytes with 80.56 % had the highest frequency among white blood cells, whereas the frequency of thrombocytes, neutrophils and monocytes were 9.56%, 7.48% and 2.45% respectively, while no basophil and eosinophil were found among the samples. Comparison of white blood cells and thrombocytes among uninfected and infected fishes to the parasites showed that amount of lymphocytes decreased by increasing infection while occurrence of monocytes increased in severe infection in comparison with uninfected stage. Occurrence of neutrophils and thrombocytes increased too. Average amount of haematocrit in uninfected, mild infection and in severe infection fishes were different and decreased. Average counting of red blood cells like haematocrit decreased in uninfected, mild infection and in severe infection, while average counting of white blood cells increased in uninfected, mild infection and in severe infection.  Statistically, the changes of lymphocytes, neutrophils, thrombocytes, haematocrit and average counting of white blood cells were significant (p=0.001).