Determination of blood biomarkers of lead pollution in Gorgan Gulf using blood indices of Mottled Goby (Neogobius melanostomus, Pallas 1814)

The present study was carried out for providing basic information on the ecophysiological damages (blood indicators) of Mottled Goby in laboratory and environmental conditions of lead contamination and finally the design of blood biomarkers of lead contamination in Gorgan Gulf. In the laboratory studies, 400 piece of fishes with the weight average of 35±7.16 g were lively caughted and the tested fishes were exposed to concentrations of 0, 3.75, 7.5 and 15 mg/L of  lead for 14 days. After the completion of the experiment, the samples of blood and  liver were collected from fishes and the samples surveyed  by the analyses of hematology and toxicology. In the field test, the samples of fish, water and sediment were prepared from 4 areas, Khozeini 1, Khozeini 2, Gharasu, and Gorgan rud. In addition to the measuring lead in water, sediment and liver tissue, the samples of blood  from caughted fishes were similarly analyzed with the laboratory conditions mentioned. According to the results, among the hematologic parameters of  Mottled Goby, monocyte, red blood cell, hemoglobin and MCHC showed a positive and significant correlation and lymphocyte and MCV showed a negative and significant correlation with accumulated lead contamination in the liver of Mottled Goby in laboratory conditions and in environmental conditions, monocyte showed, a positive and significant correlation and eosinophil showed a negative and significant correlation with the contamination of lead in the Mottled Goby liver in environmental conditions. Neutrophil also showed an increasing trend with changes of  lead contamination in liver. In total, among the blood indices of Mottled goby, the monocyte percentage of the blood was proposed as the most effective and efficient blood biomarker of lead contamination in Mottled goby, due to the high correlations and the same trend in both environmental and laboratory conditions (P<0.05).