Genotoxic and Histopathological Effects of Olive-Mill Wastewater on Lepomis gibbosus

In this study, the genotoxic and histopathological effects of olive-mill wastewater (OMW) on the tissue cells of Lepomis gibbosus were investigated. The fish were caught from Topcam dam lake (Cine/Aydin) and were exposed to the wastewater in 50-L aquariums which contained 0.5 % OMW for 3-5 and 7 days. In genotoxic investigations, a statistically significant increase was observed in the frequency of micronuclei in the L. gibbosus in experimental groups. As a result of the exposure to OMW, histopathological findings which showed a parallel increase with the amount of exposure in the gill, liver and muscle tissues were determined. In the gills, disruption of lamellae shape, shortening and breakage of primary and secondary lamellae, fusion and branching, separation in the secondary lamellae epithelium, ballooning dilation, hyperplasia in support cells and increase in mucus cells were observed. In the parenchyma of the liver, a difference in local staining, focal necrosis, haemorrhaging in necrotic areas, oedema of blood vessels, expansion in sinusoids, congestion and dilation in portal veins, deterioration of vessel walls, cytoplasmic vacuolization in hepatocytes, pyknotic nuclei, decrease in glycogen storage in hepatocytes near the central vein and aggregates of melanomacrophages were also observed. The necrosis in muscle bundles, widespread oedema between myofibrils, degeneration and separation in some muscle groups, decrease in glycogen content, intramuscular oedema and atrophy in the myofibers were determined in the experimental groups.