Effects of lead sub-lethal concentration on Blood Iron content of the common carp, Cyprinus carpio

In order to examine the effect of lead on the iron content of blood, sampling of common carp was carried out randomly from a fish culture pond in southeast of Babol by purse seine, in 2008. First of all, the experimental fish were adapted to laboratory conditions for 48 hours. Then, the effect of different concentrations of lead were examined using 3 experimental (A: 4.296 mg/l, B: 7.127 mg/l, C: 8.656 mg/l) and one control groups. There were 12 aquariums, each containing 12 fish. It was tried to apply an equal environmental condition for all of the aquariums during the experiment. Following 24, 48, 72 and 96 hours of exposure, fish were anesthetized and blood samples were taken from caudal vein. The fish average weight and length (total length) were 140.5 g, 21.8 cm, respectively. Concentrations of lead and iron have been determined by ICP-OES after acid digestion of blood samples by Microwave. This study showed that the absorption of lead and its concentration in the blood significantly increased (p<0.05) as the time passed compared to the control group. However, there was no significant trend since the blood acts as a carrier of heavy metals such as lead to the target organs.‌There was also no significant relationship (p<0.05, n=3) between increasing the amount of absorbed lead and blood iron changes. Therefore, it  may be concluded that there is no interaction between blood iron and lead concentration. Increasing trend of blood iron concentration during the experiment was also probably because of some physiological changes resulting from stress in fish.