Effect of heavy metals on physiological and histological status in liver of common carp Cyprinus carpio, reared in cages and wild in the Euphrates River, Babil / Iraq.

Abstract

Abstract The current study was conducted to examine the concentrations of some heavy metals (Fe, Zn, and Cu) in sediments, chemical and physical properties of water(Temperature, pH, Salinity, Total dissolved solid, Dissolved oxygen, Biological oxygen demand5, Alanin transporter enzyme, aspartase transporter enzyme, Alkaline phosphatase, and histological effects of the studied metal on liver of 96 cage fish and wild fish 4 fish per site Cyprinus carpio (Common carp) in the Euphrates River from October of 2018 until November of 2019. Three sites were selected on the Euphrates River in the middle of Iraq. The first site was Abu Luka, the second site was Al Saddah and the third site was the village of Al-Hussein. The results showed that in the first and second sites, the concentration of heavy metal in sediments and fish liver was greater than in the third site. In general, the cage fish at the first and second sites were higher than the wild fish. It was also noticed that the heavy metal concentration of both fish and sediment took the following order according to the seasons of the year, from the highest concentration of heavy metals to the lowest (summer > spring > autumn > winter). It was found that liver enzymes were directly affected by the presence of high concentrations of heavy Metals. So, both the ALT and AST increased in the first and second sites as compared to the third site. But the ALP value decreased with the increase in the concentration of the studied metal. The results of the histological slicing of the liver in the first and second places revealed a breakdown of the hepatocytes with the creation of gaps between the cells. Several spaces filled with remains of the destructed cells from the visceral tissue of the liver with infiltration of inflammatory cells in the infected area of the fish liver. It is the region’s first study that was concerned with the impact of heavy metal levels in the environment on cage fish and their relationship to blood components and liver enzymes.