Concentrations of calcium, iron, potassium, magnesium, phosphorus, zinc, copper, selenium and nickel were determined in the muscle tissue of seven species of fish (Plagioscion squamosissimus, Geophagus surinamensis, Prochilodus lacustres, Curimata sp., Schizodon dissimilis, Ageneiosus ucayalensis and Hypostomus plecostomus) collected from the lower course of the Itapecuru River in the state of Maranhao, Brazil. The samples were digested in a nitricperchloric solution and analyzed using an inductively coupled plasma atomic emission spectrometer, with the construction of specific calibration curves for each element. The highest concentrations of constituent minerals were found for phosphorus, potassium, nickel and magnesium (399.83, 144.60, 90.20 and 29.49mg 100 g-1, respectively) in G. surinamensi, P. lacustres and Curimata sp. The lowest concentrations were found for copper, zinc, iron and selenium (0.12, 0.51, 1.05 and 8.31mg 100 g-1, respectively) in Curimata sp., S. dissimilis, A. ucayalensis and P. squamosissimus. The concentrations of all minerals can be considered low and are below the maximum limit established by Brazilian legislation for the human ingestion of fish meat. A comparison of the seven species of fish investigated revealed no statistically significant differences regarding the concentrations of minerals, suggesting that size and different dietary habits do not exert an influence on absorption. The low concentrations of metals, such as Fe, Cu, Zn and Ni, may be related to the environmental conditions of the mouth of the river, which receives ocean inputs that produce particular tide cycles with a strong dispersion capacity, thereby diminishing residence time in the water column and reducing the availability of these metals to species of fish.
Lederer J, Enciclopedia moderna de higiene alimentar, Sao Paulo: Manole 2 (1991).
Menezes MEDS, Valor nutricional de especies de peixes (agua salgada e estuario) do estado de Alagoas, Available online: http:// bdtd.ibict.br/vufind/Record/UFAL_a98d5127a5d4efb1abf56e04fd2efd63 (2006).
Connell DW, Vowles PD, Warne MSJ, Hawker DW, Basic concepts of environmental chemistry, CRC/Taylor & Francis (2005).
Britski HA, Peixes de agua doce do Estado de Sao Paulo: Sistematica. Poluicao e Piscicultura, Comissao Internacional da Bacia Parana- Paraguai, Sao Paulo (1972).
Mees GF, The Auchenipteridae and Pimelodidaeof Suriname (Pisces, Nematognathi), Brill (1974).
Britski HA, Rosa ABS, Manual de identificacao de peixes da regiao de Tres Marias: com chaves de identificacao para os peixes da Bacia do Sao Francisco, CODEVASF, Divisao de Piscicultura e Pesca (1988).
Vari RP, Vanzolin PE, Heyer WR, Eds., Proceedings of a workshop on neotropical distribution patterns, Rio de Janeiro: Academia Brasileira de Ciencias (1988).
Santos GM, Jegu M Merona B, Catalogo de peixes do baixo rio Tocantins: Projeto Tucurui, Available online: http://horizon. documentation.ird.fr/exl-doc/pleins_textes/doc34-04/23202.pdf (1984).
Santos GM, Merona B, Juras AA, Jegu M, Peixes do baixo Rio Tocantins: 20 anos depois da usina hidreletrica Tucurui, Eletronorte, Brasilia (2004).
Piorski NM, Castro ACL, Sousa-Neto AM, in Ichtyofauna from the Cerrado of the southern Maranhao, L. Barreto Ed. North Cerrado of Brazil, USEB (2007).
Merona B, Juras AA, Santos GM, Cintra IHA, Peixes do baixo Rio Tocantins: 20 anos depois da usina hidreletrica Tucurui, Available online: http://www.eletronorte.gov.br/opencms/export/sites/ eletronorte/publicacoes/publicacoes/Os_Peixes_e_a_Pesca_no_ Baixo_Rio_Tocantins.pdf (2010).
Froese R, Pauly D, FishBase, World Wide Web electronic publication, Available online: www.fishbase.org (2015).
Greenfield H, Southgate DAT, Food composition data: production, management and use. FAO, Rome, Available online: http:// www.fao.org/fileadmin/templates/food_composition/images/FCD.pdf (2003).
Jones JB, Case VW, in Sampling, handling and analyzing plant tissue sample, R. L. Westerman Ed., Soil testing and plant analysis, Fitchburg, Soil Science Society of America (1990).
Perkin-Elmer N, Analytical methods for atomic absorption spectrophotometry agriculture, Norwalk (1973).
IUPAC, International Union of Pure and Applied Chemistry, 2nd Ed., Chemistry Compendium of Chemical Terminology (1997).