P. Bozorgzadeh - Department of Fisheries, Science and Research Branch, Islamic Azad University, Tehran, Iran
M. Shamsaie Mehrgan - Department of Fisheries, Science and Research Branch, Islamic Azad University, Tehran, Iran
N. Pourang - Iranian Fisheries Science Research Institute
S.P. Hosseini Shekarabi - Department of Fisheries, Science and Research Branch, Islamic Azad University, Tehran, Iran

This study is performed to investigate the effects of water-borne Ni۲+ on common carp (Cyprinus carpio) liver and bone metabolisms. Fish (N=۶۰; ۱۸۴.۴۰±۱۸.۵۶g) were exposed to background concentrations of Ni۲+ (based on measured LC۵۰-۹۶h: ۵.۸۲۰ mg/L), including ۰.۰۵۸, ۰.۲۹۱, ۰.۵۸۰, ۱.۷۵۰, ۲.۹۱۰ mg/L for ۳۰ continuous days. Ni۲+-exposed fish showed a rising trend in the case of serum aspartate transaminase (AST). Serum alkaline phosphatase (ALP) elevated (p<۰.۰۵) in all Ni۲+ treatments. Serum total protein, globulin, and albumin showed a transient reduction in ۰.۰۵۸, ۰.۲۹۱ and ۰.۵۸۰ mg/L Ni۲+ exposures (p<۰.۰۵). Although serum calcium level did not change significantly, serum inorganic phosphorus was elevated (p<۰.۰۵) in ۰.۵۸۰ mg/L Ni۲+. Bone isoenzyme of ALP observed in higher levels in all Ni۲+ treatments than the control group (p<۰.۰۵). Pathological damages, such as focal necrosis, pycnosis and cytoplasm degeneration were observed in liver tissues of Ni۲+-exposed fish. A higher number of osteocytes as well as osteoclasts in bone of Ni۲+-exposed fish revealed dual effect of this metal in the case of bone metabolism. Generally, low level of nickel had no significant effect on metabolic parameters of liver and bone while highest nickel treatment had adverse effects, reflecting dual effects of this metal on carp.

Nickel, Common carp, Liver histopathology, Bone histology, Blood chemistry