Evaluation of some hematological and sero-immunological parameters of common carp (Cyprinus carpio) during of overwintering

Due to the sharp decrease or lack of feeding of carp during winter and the effects of malnutrition on fish health, the aim of the study was to determine the effect of overwintering on hematological and some sero-immunological parameters of cultivated common carp (Cyprinus carpio). The samples were gathered two times (March and May) from one the earth pond in Behshar. Every time, 30 fish were capture and their average weight were 152.3 ± 14.7 and 181.2 ± 13.2 g respectively.  In this study, the amount of red and white blood cells, hemoglobin, hematocrit, mean cell volume (MCV), mean cell hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), glucose, cholesterol, triglyceride, total protein, albumin, IgM, alkaline phosphatase (ALP), certain phosphokinase (CPK) and serum lysozyme activity were evaluated. The results showed that the number of red and white blood cells, glucose hematocrit, total serum protein, alkaline phosphatase (ALP), certain phosphokinase (CPK), cholesterol, triglyceride, IgM and lysozyme activity were significantly lower in the samples were taken in March. Also, there was no significant difference between the levels of hemoglobin, albumin, MCV, MCH and MCHC despite numerical difference between two the groups. The results of this study showed that the decrease in blood, serum and immune parameters during winter were caused by decreased metabolism and lack of carp nutrition. It is inevitable and this could be one of the possible causes of winter mortality and increase their susceptibility to some infectious diseases. Therefore, it is recommended that breeders use high-quality diets and immunostimulants supplements to increase their hemato-serological parameters and immunity, by increasing the temperature and starting feeding fish actively. +