Background: Polycyclic aromatic hydrocarbons (PAHs) such as phenanthrene (Phe) represent one of the most abundant forms of organic pollutants. The aim of this study was to assess changes in plasma levels of aminotransferase enzymes, total protein and liver tissue as biomarkers of yellowfin seabream (Acanthopagrus latus) exposed to Phe for 14 d. Methods: The research was carried out in January 2016 at Khorramshahr University of Marine Sciences and Technology, Khorramshahr, Iran. Some 72 fish were injected with 2, 20, 40 and 70 mg/kg of Phe. Then tissue and blood samples were obtained at 1, 4, 7 and 14 d after injection. Results: Exposure of fish to Phe resulted in a significant increase of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and decrease of total protein after 7 d of the experiment (P<0.05). The main histopathological alteration was showed in different sampling days including nucleus margination, hypertrophy, vacuolation, melanomacrophages aggregates, sinusoid dilation, degeneration and picnotic nucleus. Degree of tissue change (DTC) of liver was recorded in the Phe-exposed fish from normal range to moderate changes. Conclusion: The studied biomarkers such as changes in concentrations of ALT, AST and total protein as well as tissue damages in liver may be served as beneficial biomarker to assess Phe toxicity in yellowfin seabream.
