The dependence of the ratio of leukocytes in peripheral blood and immunocompetent organs of the bream Abramis brama L., inhabiting the Ivankovskoye Reservoir, on the length, weight, sex and age of the fish was studied. In smears, the cell types characteristic of the species were differentiated: lymphocytes, monocytes/macrophages, neutro- and eosinophils, blast cells. The distribution of individual values of leukocyte forms for each organ was normal according to the chi-square criterion with left-sided (lymphocytes) and right-sided asymmetry (neutrophils, eosinophils and blast cells). The number of leukocyte forms did not correlate with the length, weight and age of the fish. The differences between males and females were most pronounced in the composition of leukocytes in the head kidney: males had a higher content of monocytes, neutrophils and eosinophils, and a lower content of blast cells. In the spleen of females, the relative content of neutrophils and eosinophils is higher than in males.
T. Suvorova (Sat,) studied this question.