Labeo rohita, a bioindicator for water quality and associated biomarkers of heavy metal toxicity

Abstract

This study investigated the effect of heavy metals on Labeo rohita inhabiting the Yamuna River, India. Levels of heavy metals measured in the water were as follows: Fe>Mn>Zn>Cu>Ni>Cr>Cd. Gill and liver tissue of exposed L. rohita showed a high metal pollution index, compared to reference fish collected from the Agra Canal. In the exposed fish, higher levels of creatinine and enzyme activity (alkaline phosphatase, aspartate aminotransferase, and alanine aminotransferase) were observed, while the A:G index declined. Additionally, higher TLC, lymphocytes, respiratory burst, and nitric oxide synthase activity indicated a heightened immune response. Levels of superoxide dismutase and lipid peroxidation were elevated, while catalase, glutathione S transferase, and glutathione was reduced. DNA of the exposed fish appeared deteriorated, with a greater mean tail length in comparison to the reference. Our results imply that Yamuna River water generates oxidative stress and DNA damage in L. rohita. As this river is a critical source of water and food to the native community, this could pose a threat to public health similar to that in the indicator organism.

Water quality index, Labeo rohita, and Eichhornia crassipes: Suitable bio-indicators of river water pollution

“…The low burden of heavy metals in the kidney indicates that it is working efficiently to remove them. Corroborating results to the present study were also reported by Khan et al, 2020 , Mahamood et al, 2021 in Oreochromis niloticus and L. rohita inhabiting the polluted Yamuna river. We recently reported gills and liver as the target organs of heavy metals in the Mystus vittatus and Mystus tengara fish ( Tabrez et al, 2021 ).…”

“…In another study, Ghannam (2021) also used the water pollution index and bioaccumulation factor in fish to determine the water quality and health status of the Nile River, Cairo. The poor quality of water bodies has also been reported from India's other natural freshwater resources ( Khan et al, 2020 , Mahamood et al, 2021 ). Such water quality studies become stronger and more meaningful when adverse effects are assessed on the health outcomes of bio-indicator organisms dwelling in their environment.…”

“…In one study, Shah et al (2016) reported that lymphocytopenia and low eosinophils could indicate cardiovascular disorders. The different leucocytes are commonly present in the fish blood except for basophils which are either rarely present or absent in healthy conditions ( Mahamood et al, 2021 ). We also didn't observe any basophils in a smear of both reference and exposed fish.…”

Effects of Lead and Cadmium Accumulation on Survival and Growth of the Nile Tilapia (Oreochromis niloticus)

“…According to Li & Xie (2018), fish exposed to an acute lethal concentration of cadmium are related to the loss of sodium ions, which causes disruption of the cardiovascular system, which leads to fish kill. Long-term metal exposure causes numerous histopathological changes, particularly in fish gills, that may lead to respiratory dysfunction, hypoxia and fish death (Agatha, 2010;Abdel-Baki et al, 2011;Mahamood et al, 2021). Çiftçi et al (2015a) recorded that no mortality was observed in O. niloticus exposed to 0.2 ppm Pb over 30 days, which could be due to the tested concentrations of these metals not being lethal to this species at the experimental periods tested.…”

Bagarius bagarius, and Eichhornia crassipes are suitable bioindicators of heavy metal pollution, toxicity, and risk assessment

“…Although, these countries do not have water shortage problems, but have poor water quality issues 1 , 2 . It is well known that the development of industries, urbanization, inappropriate agriculture practices, the ever-expanding population, etc., all have damaged the freshwater resources by discharging effluents, runoffs, and dumping wastes 3 . Islam 4 determined trace metals in the deep and surface water of Korotoa river, Bangladesh.…”