One hundred and twenty sole (Euryglossa orientalis) and yellowfin seabream (Acanthopagrus latus) fishes were captured from five stations at the Musa Creek (northwest of the Persian Gulf): petrochemical, Gaffari, Majidieh, Ghazaleh, and Zangi stations. Blood was collected from the caudal vein as samples. Tissue samples were also taken from the spleen and head kidney, and tissue sections were prepared according to routine histological methods. The concentrations of Hg, Pb, Zn, Cu, and Cd in the water and sediment samples were measured. The most tissue changes, the maximum concentration of C3 and C4, and the minimum amount of serum antibacterial activity and lysosomal membrane stability in fish collected near a petrochemical station were determined. This station is adjacent to the Imam Khomeini Petrochemical Complex, and it receives highly contaminated effluents from this complex. The fish collected from the Zangi station exhibited the highest lysosomal membrane stability and antibacterial activity and the lowest amounts of C3 and C4.
