Accumulation and histological transformation in the gills, liver, muscles, and skin in <i>Oreochromis</i> <i>niloticus</i> induced by mercury

Abstract

Specimens of Oreochromis niloticus (One control and 3 experimental groups) were fed diets mixed with different doses of mercury (control group = free of mercury; group 1 = 500 mg/kg; group 2 = 750 mg/kg, and group 3 = 1000 mg/kg) for 60 days in order to study its accumulation and histopathological alterations in the liver, gills, skeletal muscles, and skin. The results obtained revealed that mercury accumulation was significantly (P < 0.05) high in the liver and gills compared to the muscles and skin. The order of accumulation in these organs revealed to be liver > gills > muscles > skin. The fish fed various doses of mercury also showed histological alterations in these organs. Epithelial lifting and epithelial hypertrophy were seen in the gills of the treated fish. Fusion of secondary lamellae was also apparent. The effects were more pronounced in fish fed high doses (1000 mg/kg). Necrosis of hepatocytes and portal veins was also observed in the livers of the treated fish. Irregular muscle bundles and irregularly bigger gaps between the muscle bundles were evident in the skeletal muscles of fish fed diets with mercury, along with some structural changes in the skin of the fish fed mercury-mixed diets. The results obtained clearly indicate that mercury causes deleterious effects on the different organs of fish at even low dose (500 mg/kg).

The EU Interreg Project “GEREMIA” on waste management for the improvement of port waters: results on monitoring the health status of fish as bioindicator

“…Gill histopathological analysis revealed that the most relevant alterations found in samples from the Port of Genoa were PL and SL hyperplasia, SL hypertrophy, SL epithelial lifting, and necrosis, followed by fusion and congestion of SL with occasional granulocyte infiltration (Figs. 4 and 6); results are in accordance with literature which highlighted the presence of the same alterations in fish exposed to a contaminated environment (Al-Ghanim et al 2019;Ben Ameur et al 2015;Gad El-Hak et al 2021;Nagarjuna and Mohan 2017;Noguera et al 2019). Hyperplasia and the consequent fusion of SL, SL hypertrophy, and SL epithelial lifting are defensive changes that occurs in gill tissue to increase the distance between (Arockia Vasanthi et al 2013;Rajeshkumar et al 2015).…”

Chelation of mercury intoxication and testing different protective aspects ofLactococcus lactisprobiotic in African catfish

“…Water pollution is a fast‐growing problem of 21st century worldwide (Bassem, 2020). Contamination with heavy metals (HM) is a serious problem owing to their persistence, bioaccumulation in different fish tissues, non‐degradable nature and poisonous effects (Al‐Ghanim et al, 2019; El‐Bouhy et al, 2021; Huseen & Mohammed, 2019). Heavy metals cause disastrous effects on metabolic processes, nutritional value, health and immune status of African catfish, freshwater organisms and Zebrafish (El‐Bouhy et al, 2021; Hong et al, 2020; Kim et al, 2020), also, constitute a hazard to fish consumers (Isangedighi & David, 2019).…”

Pesticides and Heavy Metal Toxicity in Fish and Possible Remediation – A Review

“…Heavy metals induced several histopathology in different important fish organs. Heavy metals contamination resulted hyperplastic and hypertrophic epithelial, chloride and mucous cells in gills, congested capillary, jointed gill lamellae, clubbing, talangiectasis in fish gill and caused respiratory difficulties (Rajeshkumar et al, 2017;Al-Ghanim et al, 2019). Liver is very much sensitive to heavy metals in comparison to other organs and several histopathological changes (necrotic and degenerated hepatocytes, cirrhosis and lysis of hepatic cells, pyknosis, and vacuoles) observed in different extent in various fish (Kawade, 2020).…”