Abstract
Fish take up metals from the aquatic ecosystem and accumulate it in their muscle tissues and organs. The aim of the present study was to determine the role of intestinal helminths in bioremediating the accumulation of some heavy metals in the muscle tissues of the emperor fish, Lethrinu smahsena. A total of 130 fish were collected randomly from Raas Mehsen in the Red Sea, Jeddah coast, during the period of November 2015 to May 2016. The percent of total infection in L. mahsena fish was found to be 62%. Four species of Trematoda, one cestode larva and three species of Nematoda were recorded from the small intestine. Element concentrations in the infected and non-infected fish and parasites were analyzed using flame atomic absorption spectrometry. Mean concentration of individual heavy metals in trematode parasites was in the order of As> Fe> Zn> Pb> Cu> Cd. For cestodes, it was As> Fe> Zn> Pb> Cu> Cd. While in nematodes, it was in the order of As> Fe> Zn> Pb> Cd> Cu. Most heavy metals exhibit a significant decrease in fish tissues infected with helminthes. Bioaccumulation factors indicated much higher concentrating capacity of cestode parasites than fish organs. Thereby, cestode and nematode infections in marine fish could be considered to be a biological indicator of heavy metal pollution and at the same time could also minimize the bioaccumulation of heavy metals in fish tissues.