58 International Journal of Advanced Science and Research ISSN: 2455-4227 Impact Factor: RJIF 5.12 www.allsciencejournal.com Volume 2; Issue 5; September 2017; Page No. 58-63 The heavy metal lead nitrate toxicity effect on biochemical alteration in fresh water fingerlings Labeo rohita, (Hamilton, 1882) Raja P, * Puvaneswari S Department of Zoology, Annamalai University, Tamil Nadu, India Abstract The character of the environment is degenerating due to the accumulation of several pollutants either direct or in indirect way, which at last causes several unwanted effects on organisms in general and particularly on human beings. The heavy metal lead nitrate is one of the important aquatic toxic pollutant and is ubiquitous trace metal. In the present investigation, an attempt was made to assess the effect of lead nitrate on biochemical parameters in the muscles and liver tissue of Labeo rohita fingerlings. The fish were exposed to a sub-lethal dose of 1.56 mg L -1 (1/25 th of 96 hr LC50 value of lead nitrate) for a period 60 days. At the end of each exposure period, the level of protein, lipid and glycogen were analyzed in selected tissues. A significant decrease (P<0.01 and P<0.05) was noticed in all the biochemical parameters studied in treated liver and muscles tissues groups when compared to the control. Keywords: Labeo rohita, lead nitrate, biochemical parameters, liver, muscle Introduction The most common cause of water pollution in developing and developed countries is domestic and industrial waste that is directly released into streams or ponds without treatment. Adversely human activities are directly or indirectly affect the environment. Due to development activities such as construction, transportation and manufacturing not only deplete the nature resources but also produce large amount of wastes that leads to pollution of air, water and soil (Tamizhazhagan, 2015, 2016) [39, 40] . The most important source of irrigate pollution are household, agricultural and industrialized waste which are discharge into ordinary water body (Tamizhazhagan et al., 2017) [41] . These wastes mostly contain various types of pollutants such as heavy metals, radioactive substances, pesticides, herbicides and corrosive substances like acids and bases (Mhadhbi et al., 2012) [26] and these could alter physiological and biochemical parameters in fish. The survival of many aquatic species depends not only on the health status of the ecosystem, but also on the type/length of exposure to and inherent toxicities of the metal toxicants (Brungs et al., 1977) [4] . Heavy metals are among the most dangerous substances in the aquatic environment because; they persist and are harmful to aquatic organisms(Tamizhazhagan et al.,2016). Lead is a naturally occurring heavy metal which has been used in various ways including mining, smelting, refining, gasoline, battery manufacturing, electrical wiring, soldering, painting, ceramic glazing and making of stained glass. Due to its non- degradable nature, it gets into the environment and eventually enters the human and animal’s blood stream. Fish accumulate toxic metals directly through the water or indirectly through the food chain. It is accumulated in soft tissues such as gill, liver, kidneys, nervous system, and brain. (Spokas, et al., 2006; Schmitt et al., 2007; Has-Schon et al., 2008) [38, 35, 8] and could alter the physiological and biochemical parameters in fish. The body components like protein, carbohydrate and lipid play a significant role in body construction and energy production. They are involved in major physiological events and the assessment can be considered as biomarker to determine the physiological phases of organism (Martein and Arivoli, 2008). Fish are considered as a suitable biomonitors for environmental pollution and they are exposed to the heavy metals invitro and the effect of metals on fish is studied (Padmini et al., 2004) [27] . As freshwater aquaculture constitutes one-third of the total fish production in India and major carps being the dominant species (Labeo rohita, Catla catla and Cirrhinus mrigala). Hence, the aim of our present study is to examine the effect of lead nitrate on biochemical parameters of Indian carp rohu (Labeo rohita) fingerlings that forms an important candidate species in carp poly-culture systems. Materials and Methods Test Chemical and Stock solution The toxicant being studied was lead nitrate. Stock solution was prepared using analytical grade Lead Nitrate [Pb (NO3)2]. Since nitrate also cause toxicity, Lead Nitrate as such was used as a test chemical. 10gm of Lead Nitrate was dissolved in 1lit of distilled water and the required concentrations of the test media were prepared using chlorine free tap water as diluents. Stock solution was prepared every day. Experimental design The fingerlings of the freshwater fish Labeo rohita, weighing 10 ± 2gms and length 7 ± 0.2cm were procured from Venkatesh fish farm, at Pinnalur and transferred to the fibrous tank in the Department of Zoology Annamalai University. The water in the tank was aerated twice a day, the fish were fed