A Study on Biochemical Changes in the Fresh Water Fish, <i>Catla catla</i> (Hamilton) Exposed to the Heavy Metal Toxicant Cadmium Chloride

Abstract

Cadmium (Cd), one of the twenty three heavy metal toxicants, is widely used in Ni-Cd batteries manufacture, metal and mining industry, dentistry etc. because of its non-corrosive nature. Cd is released in considerable amounts through industrial effluents into soil, surface and ground water systems. These excess amounts in addition to naturally occurring levels gradually build up to toxic levels causing damage to the biota of the aquatic ecosystem. It shows biomagnification and has greater half-life periods. Cd was found to interfere with many protein and carbohydrate metabolisms by inhibiting the enzymes involved in the processes. The present study evaluates toxicity of Cd and its impact on biochemical constituents like glucose, glycogen, total proteins, lipid and free aminoacids in the fresh water edible carp Catla catla as Cd bioaccumulation can affect humans through biomagnification. Short term tests of acute toxicity were performed over a period of 96 hours using cadmium chloride. The renewal technique was followed by exposing the fish to test solutions of different concentrations in the range of 1 mg/L to 8 mg/L. Preliminary experiments were conducted to choose concentrations that resulted in the mortality of the fish in the range of 10-90%. The toxicity experiments were then conducted using the chosen concentrations of CdCl2 on the fingerlings ( Wt. 6±1 grams ) in triplicate and the LC50 was determined using simple graphic ( % Mortality Vs. Log Concentration), probit graphic ( Probit value Vs. Log concentration) and unweighted regression analysis methods. The calculated average 96-hr LC50 is 4.533 mg/L and the equation for the dose-mortality regression line was found to be Y = 2.65X + 3.368. Levels of the five biochemical constituents viz., Glucose, Glycogen, Total proteins, Lipids and Free aminoacids were determined by standard biochemical procedures in the five tissues i.e., muscle, gill, liver, heart and kidney of unexposed (Control) healthy fish and the fish exposed to 96-hr LC50 (Lethal) and sub-lethal concentrations (1/10th of the lethal dose for 7 days of exposure) of cadmium chloride. Results showed significant fall in all the biochemical constituents in all the tissues except glucose prompting to suggest that the fish cultured in the aquatic systems closer to the industrial locations would not have the expected nutritive value. The elevated levels of glucose are apparently indicative of the organism's response to the toxicant stress. Also, such fish when consumed as food lead to the deposition of the heavy metal in the soft tissues of the human body leading to exposure health effects. Key words: Toxicity; Heavy metal; Cadmium chloride; Biomagnification; Catla catla DOI: 10.3126/kuset.v3i2.2890 Kathmandu University Journal of Science, Engineering and Technology Vol.3, No.2, August 2007, pp 1-11

Influences of some pollutants on water quality of El-Bagouria Canal at Kafr El-Zayat Region, El-Gharbia Governorate, Egypt

“…While, the decreasing in glycogen content in the muscles may be due to the inhibition of hormones which contribute to glycogen synthesis. These results are in agreement with Sobha et al (2007) and Maharajan et al (2012). While, different observations were recorded by Kavidha & Muthulingam (2014), who observed a remarkable decline in the carbohydrates content due to its rapid utilization to meet the reduced energetic efficiency at long exposure to heavy metals.…”

“…This depletion may be explained on the basis of energy production during the pollutant toxicity through metabolic utilization of the ketoacids to gluconeogenesis pathway for the synthesis of glucose. These observations are similar to those obtained by Sobha et al (2007) and El-Nabarawy (2014), who attributed low protein to other several pathological processes including impairment in protein synthesis machinery, renal damage and elimination in hepatic blood flow or plasma dissolution. Unsimilar findings were notably by Zaghloul (2000), who reported increasing in total proteins in soft tissues of the fishes exposed to heavy metals.…”

“…According to the present data, the low concentration of lipids in different organs of the fish species especially the muscles could be attributed to poor storage mechanism and the use of fat reserves during spawning activity or imposition of high energy demands to counter the toxic stress beside many other factors that affect the lipids content of fish as seasonal effect, different provisioning origins and a reproduction period. The present results are nearly similar to those obtained by Sobha et al (2007) and Mohanty et al (2013) and disagree with Javed and Usmani (2015) who reported the increasing in lipids content in the internal tissues of fish exposed to heavy metals.…”

Seasonal variations in the biochemical composition of muscle and liver of marine fishes, Gazza achlamys and Ariomma indica from Visakhapatnam coast, South India.

“…7 worked on biochemical composition of Atlantic bonito at different stages of maturity. 8 investigated the effect of toxicant stress on fish biochemical concentration in exposed fish. Douglas et al, (2008) 9 observed the role of phospholipids in nutrition and metabolism of teleost fish.…”

Bioaccumulation of Trace Metals in Tissues of Rohu Fish for Environmental Risk Assessment

“…This trace metal affects the physiology of fish due to its chronic exposure to waterborne sub-lethal levels cadmium as suggested by Ricard et al [26] in the rainbow trout and by Abedi et al [27] in common carp. Acute toxicity studies of cadmium on the edible carp, Catla catla conducted by Sobha et al [28] revealed significant changes in the biochemical constituents of the fish like glucose, glycogen, total proteins, lipids and free amino acids. Reports by Abdel-Moneim et al [29] on gills and liver of Oreochromis niloticus from polluted wetland environments, Saudi Arabia showed that bioaccumulation of Cd were mostly above the WHO reference values.…”