Phagocytic and cytochemical parameters of peripheral blood leukocytes in adult and 1.5-month-old harp seal pups were studied. Phagocytic number, proportion of phagocytic leukocytes, and phagocytic activity, average number of absorbed latex particles per leukocyte, were determined. Differences between groups of seals by average values of these indicators have not been revealed. A correlation analysis revealed a significant relationship between the phagocytic activity of leukocytes and their glycogen content in adult seals (r = 0.89). Content of cationic bactericidal protein (CP) in leukocytes of adult animals was 10-12 times higher than in pups. Correlation of CP and eosinophil count in adults was high (r = 0.88). Adult had significantly more eosinophils than pups. The noted features can provide higher efficiency of phagocytosis and destruction of absorbed bacteria in adult seals as compared to pups, despite the high level of indicators of the first, absorbing, phase of phagocytosis in the latter.

Keywords: harp seal; immunity; marine mammals; phagocytosis.