OBJECTIVES: The study aimed at assessing the effects of a pyrethroid cypermethrin on common carp (Cyprinus carpio L.) on the basis of the results of acute toxicity tests and haematological, biochemical and histological examinations.
METHODS: Experimental carp were exposed to the pesticide preparation Alimetrin 10 EM in the concentration of 29.1 microg/l(-1) (96hLC(50)) corresponding to 29.1 microg/l(-1) of cypermethrin in a 96 h acute toxicity test. The results of the test and of the examinations of exposed carp were compared with the results of carp from the control group.
RESULTS: In haematological profile, the experimental group of carp showed a significant (P<0.01) increase in the number of erythrocytes, segmented neutrophile granulocytes, developmental forms of myeloid sequence and eosinophiles, and a significant (P<0.01) decrease in mean erythrocyte volume, mean erythrocyte haemoglobin and lymphocyte count. As far as biochemical indices are concerned, the exposure caused a significant (P<0.01) increase in glucose and lactate concentration and creatine kinase activity, and a significant (P<0.01) decrease in total proteins, albumins, total globulins, ammonia, lactate dehydrogenase and alkaline phosphatase in blood plasma of exposed carp compared to the control group. Histopathological tissue examinations proved random hyperaemia and perivascular lymphocyte infiltration in skin, respiratory epithelium hyperplasia and chloride cell activation in gills, and pancreas exocrine cell vacuolisation in common carp after the exposure.
CONCLUSIONS: The exposure of common carp to 29.1 microg/l(-1) of Alimetrin 10 EM caused significant shifts in haematological and biochemical profile and histopathological changes in organ tissues. The cypermethrin-based pesticide Alimetrin 10 EM was classified among substances strongly toxic for fish.