Impact of nematode helminthes on metal concentrations in the muscles of Koshar fish, Epinephelus summana, in Jeddah, Saudi Arabia

The aim of the present study was to determine the impact of nematode parasites on the metal balance of the Koshar fish Epinephelus summana. A total of 102 fish were randomly collected from the Red Sea, Jeddah coast, during the period of March to September 2014. The element concentrations in the infected and non-infected fish were analyzed using flame atomic absorption spectrometry. Nematodes were collected and described from fish liver, intestine, stomach and gonads. The results showed that intestinal and stomach nematodes caused significant decreases in both magnesium and lead and insignificant decreases in iron and calcium compared to non-infected fish. There were significant increases in potassium and sodium and insignificant increases in zinc and copper in fish infected with intestinal and stomach nematodes. Most elements significantly decreased in fish infected with gonadal nematodes, with the exception of magnesium and lead, which insignificantly decreased in comparison to healthy fish. Adult nematode infection in marine fish is considered to be a biological indicator for heavy metal pollution, and its presence can minimize the bioaccumulation of heavy metals in fish tissue and organs.