BACKGROUND: Heavy metals and metalloids are among the most stable and resistant to decomposition elements that, in the presence of high concentrations in aquatic tissues, threaten their own and human health. OBJECTIVES: The aim of this study was to determine the composition and order of the elements accumulation in the edible muscle tissue of pike from Siah Darvishan River as one of the most valuable and economical fish and also to evaluate its health for human nutrition. METHODS: In the present study, concentration of eleven elements (As, Fe, Hg, Zn, Pb, Se, Cd, Cr, Cu, Mn, Ni) in the muscle tissue of 25 pike (Esox lucius) collected with the Cast net in the summer of 2016 from Siah Darvishan River, Guilan province, Iran were surveyed by Varian Atomic absorption spectroscopy. RESULTS: The lowest and highest mean accumulation of elements were obtained as follows: Zinc 25.89 - 28.80, Iron 21.85 - 24.26, Copper 6.78 - 8.15, Manganese 1.77 - 2.12, Lead 0.68 - 0.73, Selenium 0.59 - 0.62, Arsenic 0.53 - 0.62, Cadmium 0.38 - 0.41, Nickel 0.24 - 0.28, Chromium 0.17 - 0.19 and Mercury 0.087 - 0.098 microgram per gram dry weight, respectively. CONCLUSIONS: According to the results of this study, mean concentrations of all elements in the muscle tissue of pike, except the four elements Manganese (1.956 ± 0.178), Lead (0.698 ± 0.028), Arsenic (0.572 ± 0.044) and Cadmium (0.393 ± 0.018) were observed to be lower than explained threshold limit value (TLV) of FAO/WHO international standard.

Introduction: The study examined the concentration of total mercury and correlation coefficients between fish size or FCF (condition factor) and the content of Hg in muscle tissue of six freshwater fish: bream (Abramis brama L.), roach (Rutilus rutilus L.), whitefish (Coregonus lavaretus L.), vendace (Coregonus albula L.), perch (Perca fluviatilis L.), and pike (Esox lucius L.). Material and Methods: The fish were caught from the Lake Pluszne located in the Olsztyn Lake District (Poland). Mercury was analysed by atomic absorption spectrometry using Milestone DMA-80 (with dual-cell). Results: The content of the element in the muscles of the examined fish was as follows: pike (0.197 mg/kg) ≈ perch (0.173 mg/kg) > vendace (0.114 mg/kg) ≈ roach (0.095 mg/kg) and roach ≈ whitefish (0.065 mg/kg), and whitefish ≈ bream (0.042 mg/kg) (p ≤ 0.05). In all cases, the content of mercury correlated positively with the body weight and total length of the fish. Only the correlation coefficients between mercury concentration and weight or length of bream were slightly higher (0.979 and 0.977 respectively, p ≤ 0.001). The length and weight relationship of the fish was also determined. Conclusion: The results showed that the levels of mercury were lower than the maximum acceptable limit established by the Commission Regulation (EC) No 629/2008 of 2 July 2008. Thus, they are safe from consumer health point of view.