Impact of Polycyclic Aromatic Hydrocarbons on the Ovary of Clarias gariepinus in Two Canals of Al-Minufiya Governorate, Egypt

The study aimed to quantify polycyclic aromatic hydrocarbons (PAHs) in the sediments and to assess their impact on the ovary of the catfish (Clarias gariepinus) obtained from two Delta Nile Canals, Bahr Shebeen (Site 1), and El-Bahr El-Pharaouny (Site 2) Canals in Al-Minufiya Governorate, Egypt. Eight female catfish specimens were collected from various localities at two examined sites during July 2023. Furthermore, Σ16 PAHs were quantified in sediments. Some female sex hormones were evaluated. Morphology, maturation and histopathological changes in the ovary were elucidated. The results indicate that the mean values of PAHs including, naphthalene, phenanthrene, chrysene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)Pyrene, dibenzo(a,h)anthracene and benzo(g,h,i)Perylene were higher in sediment from site 2 compared to site 1. In contrast, the mean values of pyrene, benz(a)anthracene, and indo(1,2,3-cd) pyrene were higher in sediment from site 1 than site 2. Fluorene value (1.006±1.743) was exclusively detected in sediment at site 2.Acenaphthylene, acenaphthene, anthracene and fluoranthene were completely absent in the sediments of the two investigated sites. The mean value of progesterone (ng/ml) was higher in serum of fish collected from site 1 in comparison with site 2. On the other hand, the estradiol (E2) (pg/ml) was greater in serum of fish obtained at site 2 than site 1. The ovarian morphology offishesfrom site 1 exhibited a normal structure, while slight abnormalities were observed at site 2. The ovary of the catfish from site 1 exhibited the lowest incidence of atretic oocytes, whereas site 2 displayed the lowest percentage of mature oocytes alongside the highest occurrence of atresia. Microscopic examinations revealed degenerative alterations (atresia) in certain oocytes leading to the adherence of their cellular covering. This study revealed that elevated levels of PAHs result in heightened histopathological changes in the ovaries of the catfish, therefore serving as effective biomarkers for assessing PAHs in freshwater ecosystems.