Histopathological effects of silicone dioxide nanoparticles on the larval period Labidochromis caeruleus (Fryer, 1956) (Teleostei: Ciclidae)

In this study, the effects of silicon dioxide nanoparticles (SiO2NP) were investigated histologically on fish larvae of Labidochromis caeruleus (L. caeruleus). For this purpose, rootstock fishes were multiplied in the laboratory and one day larvae were divided into two groups as control and experimental groups. No treatment was performed in the control group and SiO2NPs were administered to the experimental groups in three different doses (50 mg/L, 100 mg/L and 200 mg/L). Substance administration was carried out for 96 hours. 50% of the aquarium water was renewed at 24-hour intervals without changing the concentration of nanoparticles in the test solution. The larvae of all groups were subjected to routine histological procedure and prepared as a permanent preparation. Some structural changes were found in the gill, liver, eye and brain tissues of the fishes of all experimental groups applied SiO2NPs. In the gills, disruption of lamellae shape, shortening and breakage of primary and secondary lamellae, fusion and branching, separation in the secondary lamellae epithelium. Oedema in hepatic capsule, picnotic nucleus in hepatocytes, necrosis in different parts of the parenchyma and large vacuoles were observed in liver. Thinning of the corneal layer in the eye tissue, separation of the lens epithelium and fragmentation of the lens fibers were noted. In the brain tissue, only in the high dose group, astrocytes were observed intensely in the anterior part of the olfactory region, medulla oblongata and spinal cord. These structural changes are advanced in gill and liver tissues, moderate in eye, mild in brain. Key Words: Silikon dioksit, Nanoparticule, Labidochromis caeruleus, Histopathology.