EN
The purpose of the work was to adapt the methods of thrombocytes isolation from the peripheral blood, their absolute number determination and an attempt to evaluate their phagocytic activity. The elaborated technique of thrombocytes isolation in the ACD liquid enabled to separate in homologous plasma approximately 80 per cent of those cella, i.e. 23 850 in 1 mm³ of the plasma (± 7160). The above method allowed to preserve, like in the full blood, proper conditions for thrombocytes. It was found that the number of thrombocytes from healthy fish was 29 720 ± 6830 in one mm³ and the value of phagocytic index and per cent of phagocytic cells were 1.48 ± 0.38 and 18.83 ± 4.13, respectively. There was found 5 various forms of thrombocytes differing with the shape of the cell and nucleus, and the distribution and colour of the cytoplasm.