Investigation of Brain of Cirrhinus mrigala Exposed to Mercury by Spectroscopic Analysis

Mercury (Hg) is highly toxic, nonessential, persistent, immutable and nonbiodegradable metal and is highly toxic to animals and cause death and sub lethal pathology of aquatic animals. The present study has been undertaken to explore the toxic effects of mercury on fish brain and to detect the spectral changes after the exposure. The samples were prepared after a chronic exposure of C. mrigala to sub lethal concentrations (1/20th and 1/10th of LC₅₀ values 0.0206 ppm and 0.0402 ppm) of mercuric chloride for a period of 30 days. The samples were characterized for their structural study using X-ray diffraction (XRD), and it shows the amorphous nature. Scanning electron microscopy (SEM) technique has been used to study the surface morphology of C. mrigala brain. The spectroscopic techniques are distinguished among the currently used method of monitoring animal tissues and their components. The IR, XRD, SEM and PL, were preferred as little preparation of samples is necessary and changes in the tissue chemistry produced by metal exposure are evident. Significant differences in absorbance areas and intensities between control and metal exposed tissues showed the alterations in biochemical content. The present study can be used to correlate the overall biochemical status of the tissues with histopathological changes undergone at cellular level after chronic exposure to mercury.