EN
Studies were carried out on the number of thrombocytes and their phagocytic activity represented by the engulfing indices of thrombocytes (Ipt) and by the percentage of engulfing thrombocytes (%tp) in carps aged from 2 months to 5 years. It was determined that the number of thrombocytes increases in carps with the increase of age. The value of Ipt and %tp increases in carps aged from 2 to 13 months, but Ipt increases in fish aged from 17 months to 5 years. The value of %tp in the fish aged from 17 months to 5 years is stable.