COMPARISON OF TRACE ELEMENTS CONCENTRATION AMONG SEX OF Litopenaeus vannamei

COMPARISON OF TRACE ELEMENTS CONCENTRATION AMONG SEX OF Litopenaeus vannamei Araújo, L.N.C.P. ( ¹ ) ; Silva, E. (1) ; Oliveira, H.M (1) ; Viana, Z.C.V. (2) ; Santos, V.L.C. (2) edevaldos@yahoo.com.br (1) Universidade Federal de Campina Grande, Campus de Patos PB, Brasil. (2) Universidade Federal da Bahia, Salvador - BA, Brasil. CNPq, FABESB. ABSTRACT The consumption of shellfish has been growing rapidly due to the expansion of shrimp culture. Most shrimp farms are located near the sea coast, being susceptible to chemical pollutants such as trace elements. In this paper we present a comparative study of the distribution of Zn, Mn, Cu, Fe in tissues (muscle, viscera and exoskeleton) of Litopenaeus vannamei (male and female) from shrimp farms located around the Todos os Santos Bay, Salvador - Bahia. Shrimp samples (Litopenaeus vannamei) were collected in two shrimp farms sites located around in the Todos os Santos Bay, Bahia Brazil: Salina das Margaridas SAL and Santo Amaro SAM. Composite sub-samples of muscle tissue, exoskeleton and viscera from 76 to 120 individuals were used for analysis. An inductively coupled plasma optical emission spectrometer (ICP OES) with axially viewed configuration was employed for determinations of trace elements (Cu, Zn, Mn, Fe). Significant differences between males and females from the same locality were not observed only between different locations (Mn and Fe). The trace elements distribution in tissues were, in descending order: Zn: viscera > muscle > exoskeleton; Fe: exoskeleton > muscle; Mn and Cu: viscera > exoskeleton > muscle. For human consumption, the values found for zinc and copper concentration in all shrimps are below the tolerance limit set by ANVISA. Keywords: Farm shrimp, seafood, ICP OES

RESUMO O consumo de crustáceos vem crescendo rapidamente, graças à expansão da cultura de camarão. A maioria das fazendas de camarões é localizada próxima da costa marítima, sendo suscetíveis a poluentes químicos tais como elementos traço. Nesse trabalho foi realizado um estudo comparativo da distribuição de Zn, Mn, Cu, Fe nos tecidos (músculo, víscera e exoesqueleto) de Litopenaeus vannamei, macho e fêmea, de carciniculturas localizadas em torno da Baia de Todos os Santos, Salvador Bahia. As amostras de camarão (Litopenaeus vannamei) foram coletadas em duas carciniculturas localizadas em torno da Baia de Todos os Santos, Bahia - Brasil: Salina das Margaridas - SAL e Santo Amaro - SAM. As subamostras de músculo, exoesqueleto e vísceras de 76 a 120 indivíduos foram usadas para análises. Para a determinação dos elementos traço (Cu, Zn, Mn, Fe) foi utilizado o Espectrômetro de Emissão Óptica com Plasma Indutivamente Acoplado (ICP OES) com vista axial. Significantes diferenças entre machos e fêmeas da mesma localidade não foram observadas, apenas entre machos e fêmeas entre localidades diferentes para o manganês e o ferro. A distribuição dos elementos nos tecidos foram, em ordem decrescente: Zn: víscera > músculo > exoesqueleto; Fe: exoskeleton > músculo; Mn and Cu: víscera > exoesqueleto > músculo. Para consumo humano, os valores encontrados para as concentrações de zinco e do cobre, em todos os camarões estão foram abaixo do limite tolerável pela ANVISA. Palavras-chave: Carcinicultura, Frutos do Mar, ICP OES. INTRODUCTION Over the past 20 years the growth of shrimp farms has increased, mainly in the Southeast and West Asia, and Latin America and other tropical regions (GRÄSLUND and BENGTSON, 2001). The industry is a shrimp farm producing sector of great importance to many countries 2

in Asia (GRÄSLUND, 2003). It is estimated that the global consumption of crayfish is around 1.5 kg/capita/year (FAO, 2004). Shrimp farms are usually located near the coast and use seawater directly from the coastal area to use in shrimp farming (WU and CHEN, 2004). However, the coastal seawater is usually contaminated by various kinds of chemical pollutants mainly by human activities. Among these chemical contaminants are trace elements. These potential contaminants, although their origins are also natural sources, most of it are the result of human activities. Its accumulation in the aquatic environment may favor a probable bioaccumulation and biomagnification in organisms throughout the food chain of the aquatic ecosystem. The major anthropogenic sources are: industrial processes of minerals and metals, metals leaching of waste, solid waste and continental runoff, and animal and human excretion (MESTRINHO, 1998). The metals in ionic forms, free or associated with other chemical species, have important roles in biological systems of organisms. Some of them are considered essential because of their disabilities cause diseases to the body, which can be minimized or extinguished with supplemental feeding element. 3

Elements such as copper (Cu), zinc (Zn), manganese (Mn) and iron (Fe) are considered essential elements for both crustaceans and to the man, participating in many metabolic reactions in the body. However, its excess can cause damage and/or diseases that may be incompatible with the life of the animal in the environment and to man as a consumer in the food chain. This paper presents a comparative study of the distribution of metals in different tissues and in both sexes of the species cultivated vannamei shrimp Litopnaeus carciniculturas into two distinct regions around the Baia de Todos os Santos (BTS) in Salvador - Bahia. In addition, levels of trace elements concentrations were compared with acceptable limits for human consumption in Brasil. MATERIAL AND METHODS Shrimp samples (Litopenaeus vannamei) were collected directly from the two sites: (Salina das Margaridas SAL, Santo Amaro SAM). They were caught in shrimp farms located around in the Todos os Santos Bay (Bahia Brazil), between December 2005 and January 2006. Composite sub-samples of muscle tissue, exoskeleton and viscera from 76 to 120 individuals were used for analysis. The samples were stored individually in sterile polyethylene vials at 20 o C, freeze-dried and homogenized. They were collected using a non-metallic net. Each 4

white shrimp weighed 19 24 g, all market size. The humidity percentage was 77 ± 1%. Masses of 200 mg of samples were directly introduced into PTFE closed vessels with volumes of 23 ml. A volume of 2.0 ml of ultrapure nitric acid solutions was added to each vessel. Then, a volume of 2.0 ml of H 2 O was also added to each reaction vessel. Parr bombs were sealed and put in a muffle furnace set at 110 ± 10ºC and remained at this temperature during 12 h. After cooling down at room temperature, solutions were transferred to glass volumetric flasks and volumes were made up to 10 ml with water. All the materials used in the experiments were previously washed in ultra pure water, and a stainless steel knife was used to cut the tissues. The precision and accuracy of the method employed for the determinations were validated by analysis in triplicate of certified reference materials (CRM) NIST 1566b Oyster Tissue, using the same analytical procedure. The recovery rates were: Cu (90%); Zn (96%); Mn (89%) e Fe (102%). The limit of detection were (µg g -1 /dry weight): Cu (0.013); Zn (0.003); Mn (0,0003) e Fe (0.007). Analytical blanks were run in the same way as the samples and the concentrations were determined using the standard solutions prepared in the same acid matrix. 5

All reagents were of analytical grade unless otherwise stated. Ultrapure water (Milli-Q, Millipore, USA) with conductivity lower than 18.2 mω cm -1 was used throughout. The multielement reference solutions were prepared daily from 1000 mg L -1 stock solutions of each element (Titrisol, Merck, Germany). Each reported result was the average value of the three analyses. The results were offered as means±sem. One-way ANOVA was utilized to compare the data by sex and by tissue. Results were considered significant at <0.05. RESULTS AND DISCUSSION The concentrations of trace elements (Zn, Mn, Cu, and Fe) are in Table 1. In general, there were siginificant variations (p<0.05) between the tissues for all elements determined. In general, their distribution in tissues were comparable with those reported in other regions of the world, being in descending order: Zn: viscera > muscle > exoskeleton; Fe: exoskeleton > muscle; Mn and Cu: viscera > exoskeleton > muscle. Significant differences between males and females from the same locality were not observed only between different locations (Mn and Fe). 6

When shrimp is exposed to excess zinc in a polluted environment, the rate of concentration of that component increases in its body, but it has Organic regulating the excess is eliminated by excretion. Commonly, the concentration of zinc in the body of this crustacean is about 50-120 µg.g -1. Values above 200 mg g -1 would lead to his death (RAINBOW and MOORE, 1986). The presence of zinc in a higher concentration in the exoskeleton of samples is related probably to the availability of the metal substrate being adsorbed by the exoskeleton of the animal. The high concentration of copper in the organs may be due to adsorption material adhered on the gills instead of passing into the metabolic pathway metal (SZEFER et al. 1,990; BAMBANG et al, 1995). Iron levels, were generally larger in the exoskeleton to the muscle. The wide variation between the concentrations of different locations can also be attributed to the difference in chemical composition influences of sediment and pore water of the sea and their salinity waters where shrimp were cultured (SADIQ et al, 1992). 7

Table 1. Concentrations (µg g -1 dry weight) of trace elements in shrimp tissues from the Todos os Santos Bay, Bahia, Brazil. Zn M n Tissue SAL Female SAL Male Muscle 44.0 ± 0.9 40.8 ± 07 Viscera 25.8 ± 4.1 28.0 ± 07 Exoskeleton 57.8 ± 2.6 53.7 ± 09 Muscle 0.40 ± 0.03 0.40 ± 002 Viscera 1.30 ± 0.1 1.00 ± 009 Exoskeleton 0.30 ± 0.01 0.40 ± SAM Female SAM Male 34.5 ± 1.2 36.6 ± 0.2 25.5 ± 53.2 12 ± 2.30 06 ± 006 ND 9.80 ± 20.3 ± 0.3 52.2 ± 0.5 2.10 ± 0.01 001 001 Muscle 30.1 ± 0.1 32.6±0.4 28.7±0.4 37.8 ± 0.2 Cu Viscera 111.0 ± 4.0 118.0±1 120.0±4. 104.0 ± 1 0 Exoskeleton 88.2 ± 8.9 77.6±1.1 65.2±1.1 70.2 ± 0.7 Muscle 94.2 ± 0.6 86.0 ± 69.5 ± 63.4 ± 0.4 02 32 Fe Viscera 112.0 ± 3.0 96.9 ± 60.7 ± 65.8 ± 5.6 26 18 Exoskeleton 111.0 ± 4.0 118.0 ± 66.5 ± 71.9 ± 2.1 Farm shrimp: SAL - Salina das Margaridas; 10 SAM - Santo 84 Amaro. ND Not determined. ND 9.80 ± 0.30 The variations of the iron and manganese concentrations between locations cultivation was significant. This variation is related to the variation in water salinity between the shrimp farms, as shown by iron, with the low salt content tend to accumulate higher concentration of manganese in the tissues (MÉNDEZ et al, 1998) mainly in calcified tissues (EISLER, 1987). 8

According to the Agência Nacional de Vigilância Sanitária (ANVISA, 1965), the elements, zinc and copper, had values below the maximum tolerable and is adequate for human consumption. ANVISA does not establish threshold values for intake of iron and manganese in foods. CONCLUSION There were siginificant variations (p<0.05) between the tissues for all elements determined. Significant differences between males and females from the same locality were not observed only between different locations (Mn and Fe). The trace elements distribution in tissues were, in descending order: Zn: viscera > muscle > exoskeleton; Fe: exoskeleton > muscle; Mn and Cu: viscera > exoskeleton > muscle. For human consumption, the values found for zinc and copper concentration in all shrimps are below the tolerance limit set by ANVISA. 9

REFERENCES ANVISA - Agência de Vigilância Sanitária -, Brasil. Decreto nº 55871, de 26 de março de 1965. Acessado em 28 de maio de 2013. Disponível online em: http://elegis.bvs.br/leisref/public/showact.php?id=22 BAMBANG, Y., THUET, P., CHARMANTIER-DAURES, M., TRILLES, J.P., CHARMANTIER, G. Effect of copper on survival and osmorregulation of various developmental stage of the shrimp Penaeus japonicus bate (Crustacea, Decapoda). Aquatic Toxicology. 1995; 33: 125-139. EISLER, R. Polyciclic aromatic hydrocarbon hazards to fish, wildlife and invertebrates: a synoptic review. U.S. Fish and Wildlife Service. Biological Report 85: 81p.,1987. FAO Food and Drug Administration. Yearbooks of Fishery Statistics Summary tables. Acessado em 28 de maio de 2013. Disponível on line em: ftp://ftp.fao.org/fi/stat/summary/default.htm. GRÄSLUND, S., BENGTSON, B. Chemical and biological products used in southest Asian shrimp farming, and their potential impact on the environment a review. The Science of the Total Environment 2001; 280: 93-131. GRÄSLUND, S., HOLMSTROM, K., WAHLSTROM, A. A field survey of chemicals and biological products used in shrimp farm. Marine Pollution Bulletin. 2003; 46: 81-90. MENDÉZ, L. ACOSTA, A., RACOTTA, I. Mineral concentrations in muscle and hepatopâncreas of newly caught wild and hatchery-exhausted spawners of pacific white shrimp, Penaeus vannamei. Journal Applied Aquiculture. 1998; 4: 17-26. MESTRINHO, S. Estudo do comportamento Geoquímico dos Metais Pesados nos Sedimentos da região estuarina do Rio Paraguaçu Bahia: Recursos minerais e Hidrogeologia. Tese (Doutorado em Recursos Minerais e Hidrogeologia). Instituto de Geociências. USP, São Paulo. 1998. RAINBOW, P. S., MOORE, P. G. Comparative metal analyses in amphipod crustaceans. Hydrobiologia. 1986; 141: 273-289. 10

SADIQ, M., ZAIDI, T. H., HODA, A., MIAN, A. A. Heavy metal of health significance in comonly consumed shrimps in the eastern province of Saudi Arabia. 1995; 29, 313-319. Journal Environmental Science and Health. SZEFER, P., SZEFER, K., SKWARZEC, B. Distribution of trace metals in some representative fauna of the Southern Baltic. Marine Pollution Bulletin. 1990; 21: 60-62. WU, J.P., CHEN, H.C. Effects of cadmium and zinc on oxigen consumption, ammonium excretion, and osmorregulation of whit shrimp (Litopenaeus vannamei). Chemosphere. 2004; 57:1591-1598. 11