EN
The studies were done on 90 carps Ki of a 60-80 g weight exposed to permethrin at a concentration of 0.3 pg/L of water for 28 days (group 1) or 11 pg/L for 14 days (group 2). Immunological examinations were done with the blood of fish in group 1 after 4, 7, 14, 21, and 28 days, and in group 2 after 4, 7 and 14 days after the use of permethrin. Immunological examinations were performed after 7 and 14 days from the end of permethrin action. Group 3, untreated, served as a control. It was found that permethrin at a concentration of 0.3 pg/L significantly decreased metabolic activity of neu- trocytes and the level of blood lysozyme after 28 days of exposure. Permethrin at a concentration of 11 pg/L caused death of about 50% of the examined individuals after 14 days exposure. Granulocytosis, monocytosis and unphy- siological nuclear division in neutrocytes and lymphocytes were noted. During the whole period a significantly decreased metabolic activity of neutrocytes and blood plasma lysozyme level were observed. After transport of the fish into clean water, the examined parameters returned to physiological value in group 1 after 14 days, while in group 2 all the parameters had lower values than those in the control group.