Abstract
Deltamethrin, a synthetic pyrethroid pesticide, potential toxic pollutant and significant direct risk to the aquatic ecosystems, was investigated in the present study for its toxic impact on adult monosex Nile tilapia on the basis of acute static bioassay test, and comparison of clinical, biochemical and haemato logical examinations with deltamethrin-free control group. The 96
hLC
50 value of deltamethrin for monosex tilapia was 14.6
μg/L. The abnormal behavioral responses and toxic symptoms were described. Fish exposed to the higher deltamethrin concentration (15
μg/L) for 96
h showed significantly higher lymphocytes, total leucocytic and erythrocytic counts, haemoglobin percentage and packed cell volume content and significantly lower neutrophils compared to the control group. Deltamethrin caused adverse effects in the form of hypoproteinemia, hypoalbuminemia, hypercholesterolemia, hypoglycemia and significant increase of serum aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase activities. The results provide evidence that deltamethrin pollution may have adverse impacts and was highly toxic to monosex tilapia.