69 J. Ecophysiol. Occup. Hlth. 12 (2012) 69-76 ® 2012 The Academy of Environmental Biology, India Effects of sub-lethal dose of nickel on the biochemical parameters in the tissues of female crab Scylla serrata, from Mumbai coast. Abstract: The effects of sub-lethal concentration of nickel on the biochemical composition such as glycogen, protein, cholesterol, lactic acid, pyruvic acid in gills, hepatopancreas, muscles and sugar contents along with haemolymph in female crab, Scylla serrata procured form local fish market in Mumbai (Sassoon Dock) were studied. The female crabs were exposed to sub-lethal dose of nickel LC and LC were 200ppm and 500ppm 0 50 respectively. Among the control set the glycogen contents were found to be the highest in muscles (44.616±0.225 mg/gm wt); protein contents were maximum in gills (66.5232±0.170 mf/gm wt); cholesterol contents were highest in ovary (2.009±0.006 mg/gm wt). The sub-lethal dose of nickel caused decline in the contents of glycogen (1.030±0.0141), protein (11.299±0.055), cholesterol (1.373±0.008) and pyruvic acid (0.440±0.195) in most of the tissues studied. The lactic acid contents increased in all the tissues studied in response to the exposure of nickel. The sugar and lactic acid contents in haemolymph were elevated as a result of exposure whereas the contents of protein, cholesterol and pyruvic acid in haemolymph declined due to the sub-lethal exposure in female crabs. Key words: Scylla serrata, Nickel, Glycogen, Protein, Cholesterol, Lactic acid, Pyruvic acid. Introduction Nickel compounds are among those chemicals which are much sought after as these are used in varied aspects of industry like electroplating, electroforming and for the production of nickel batteries, electronic equipments, as a component of alloy to be used for the manufacture of tools, machinery, armaments, appliances, jewelry, medical prostheses etc. Further nickel is among the listed priority pollutants and is regarded as one of the major hazardous and noxious heavy metals which are potential component to human health and the biota in metallic as well as in combined form. Paez-Osuna and Torn-Mayen (1996) have reported on the contamination of coastal waters by various forms of pollutants, all these affect the marine biota and human adversely and effectively. Jewett and Naidu (2000) found that various metal ions are distributed in the tissues such as muscles, hepatopancreas of crab, Paralithodes camtischaticus. Darllinger and Kaut (1985) reported that when fish living in polluted fresh water bodies with nickel in sediment and contaminated food, nickel is ingested. Gautam and Sharma (2012) have reported that when fresh water fish, Clarius batrachus was exposed to copper nitrate (chronic dose, 2.5mg/l) for 30 days, cadmium and iron contents showed variations in liver and kidney; it was found that copper affected calcium metabolism in liver and iron contents were not affected in liver but in kidney it got accumulated. Chou et al., (2002) have reported that crustaceans accumulate heavy metals from the environment and many of them are used as bioindicators. Sokolova and Sokolova (2005) have studied the effects of Cd on oyster and Valarmathi and Azariah (2003) have evaluated the effects of Cu on the enzyme activities in 1 V. Mayekar, M. Pathare, G. Afonso, V. T. Mohite, Y. K. Lahir and *P. D. Raut Department of Zoology, Thakur College of Science and Commerce, Kandivli (E), Mumbai, India Department of Zoology, The Institute Science, Mumbai, India 1 Department of Environmental Science, Shivaji University, Kolhapur, India * Email : dr.pdraut@yahoo.co.in