Histopathological alterations in the liver of the sharptooth catfish Clarias gariepinus from polluted aquatic systems in South Africa

Abstract

There is a need for sensitive bio-monitoring tools in toxicant impact assessment to indicate the effect of toxicants on fish health in polluted aquatic ecosystems. Histopathological assessment of fish tissue allows for early warning signs of disease and detection of long-term injury in cells, tissues, or organs. The aim of this study was to assess the degree of histopathological alterations in the liver of C. gariepinus from two dams in an urban nature reserve, (Gauteng, South Africa). Two dams (Dam 1 and Dam 2) were chosen for their suspected levels of toxicants. Water and sediments were sampled for metal and potential endocrine disrupting chemical analysis. A quantitative and qualitative histology-based health assessment protocol was employed to determine the adverse health effects in fish. The analysis of blood constituents, fish necropsy, calculation of condition factors, and hepatosomatic indices were employed to support the findings of the qualitative and quantitative histological assessment of liver tissue. Assessment of the liver tissue revealed marked histopathological alterations including: structural alterations (hepatic cord disarray) affecting 27% of field specimens; plasma alterations (granular degeneration 98% and fatty degeneration 25%) of hepatocytes; an increase in melanomacrophage centers (32%); hepatocyte nuclear alterations (90%); and necrosis of liver tissue (14%). The quantitative histological assessment indicated that livers of fish collected from Dam 1 were more affected than the fish livers collected from Dam 2.

A histopathological study on the freshwater fish species chub(Squalius cephalus) in the Karasu River, Turkey

“…Thus, congestion can be considered an indicator of stress in fish due to the presence of xenobiotic chemicals (Rezende et al, 2014). Marchand et al (2009) observed histopathological alterations in the liver of Clarias gariepinus from polluted aquatic systems in South Africa and found an increase in melanomacrophage centers, hepatocyte nuclear alterations, and necrosis of liver tissue. Necrosis is strongly associated with oxidative stress (Li et al, 2000).…”

Biochemical and histological assessment of some heavy metals on Biomphalaria alexandrina snails and Oreochromis niloticus fish in Lake Burullus, Egypt.

“…Histopathological assessment of fish tissues allows for early warning signs of disease and detection of long-term injury in cells, tissues, or organs (Marchand et al, 2009). The use of physiological and biochemical parameters as indicators of histopathological changes have been widely used as biomarkers in the health evaluation of animal organisms (El-Khayat et al, 2015a).…”

Biomarkers in European perch (Perca fluviatilis) liver from a metal-contaminated dam lake

“…Exposure to trace metals may cause histological changes in the liver and a histological investigation of exposed specimens may therefore produce meaningful results (van Dyk et al 2007;Marchand et al 2009). The present study demonstrates that the reference fish liver generally exhibited a normal architecture with a typical parenchymatous appearance and there were no pathological abnormalities.…”

“…Hinton & Laurén (1990), Bernet et al (1999), , Cazenave et al (2009) and Marchand et al (2009) consider that the different changes in many biochemical and morphological parameters of fish may be used as successful biomarkers for toxic effects of xenobiotics such as trace metals. Initial effects of metal pollution may be evident only at cellular or tissue levels before significant changes are identified in fish behavior or external appearance.…”