Evaluation of Acute Toxicity of Metals Mixture and Bioaccumulation in Freshwater Fish  

Saima Naz , Muhammad Javed
Department of Zoology and Fisheries, University of Agriculture, Faisalabad, Pakistan
Author    Correspondence author
Bioscience Methods, 2013, Vol. 4, No. 3   doi: 10.5376/bm.2013.04.0003
Received: 29 Apr., 2013    Accepted: 27 May, 2013    Published: 03 Jun., 2013
© 2013 BioPublisher Publishing Platform
This is an open access article published under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

A study was carried out to investigate acute toxicity (96-hr LC50 and lethal concentrations) of waterborne metal mixture (Fe+Ni) for the fish, Catla catla, Labeo rohita, Cirrhina mrigala, Ctenopharyngodon idella and Hypophthalmichthys molitrix. The degree of bioaccumulation of metals in fish body organs viz. gills, liver, kidney, fins, bones, muscle and skin at both 96-hr LC50 and lethal concentrations were also determined. Mortality upon the 90-day old fish species was used as a criterion of toxicity during these experiments. With three replications for each test dose, the tests were performed, separately, at constant temperature (30℃), pH (7) and hardness (200 mg/L) of water. Against metals mixture (Fe+Ni), the overall sensitivity of five fish species, determined in terms of LC50 and lethal concentrations varied significantly. Regarding overall sensitivity of five fish species, Hypophthalmichthys molitrix were significantly more sensitive to metals mixture, followed by that of Labeo rohita, Ctenopharyngodon idella, Catla catla and Cirrhina mrigala. The concentration of both metals in fish body organs were determined by using Atomic Absorption spectrophotometer. Fish kidney exhibited significantly higher ability to amass both these metals during acute exposure of metal mixture. Accumulation of the metals in fish body followed the general order: kidney>liver>skin>gills>fins>muscles>bones. During both 96-hr LC50 and lethal concentrations fish showed significantly higher accumulation of iron than that of nickel in their body.

Acute toxicity; Bioaccumulation; Metal mixture; Fish; Fe; Ni

Aquatic pollution with metals is a worldwide ecological problem. Among different pollutants, heavy metals are distinctive in their action due to their non-biodegradability (Javed and Abdullah, 2006), susceptibility of bio-magnification in food chain (Khare and Singh, 2002) and their consequences on the environmental stability of the beneficiary aquatic body and variety of aquatic organisms (Farombi et al., 2007). Due to damaging effects of metals to aquatic flora and fauna, it is crucial to observe their toxicity to the key edible species, because this will present a warning sign of sequential and spatial level of the process, as well as assessment of possible impacts of metal on the human health (Fernandes et al., 2007).

Quantitative factor involving survival and mortality of fish are used to estimate the effects caused due to acute toxicity of different toxicants for the fish (Azmat et al., 2012) and to assess the sensitivity of various fish species against metal’s toxicity (Naz et al., 2012 ). Fish is more susceptible to metals accumulation when the concentration of metals exceeds the permissible limits in the aquatic environment (Rauf et al., 2009) and serious health problems were induced due to consumption of the metals contaminated fish by humans. Fish can uptake metals via gut, skin and gills; however which course is more crucial is based upon existing environmental conditions (Javed, 2012a).

However, metals amassing in tissues reveal the past exposure of fish via water or food that can work as bio-indicator of metallic pollution of the atmosphere (Jabeen et al., 2012). Different organs of the fish take up heavy metals due to the affinity between them. During this process, these heavy metals are accumulated at different levels in different body organs of the fish (Javed, 2012b; Bervoets et al., 2001).

Accumulation of heavy metals in fish is generally based upon concentration of water in sambient water and period of exposure, however many other factors such as pH, water salinity, hardness and temperature, size and age, ecological needs, life cycle, capture season and feeding habits of fish also play considerable role in accumulation of metals (Naz et al., 2012). Studies conducted on numerous fishes showed that heavy metals amend the biochemical parameters and physiological activities both in blood and tissues (Basa and Usha Rani, 2003; Javed, 2012a). The toxic effects of heavy metals have been reviewed (Naz and Javed, 2012), including bioaccumulation (Javed, 2012b; Vinodhini and Narayanan, 2008). Iron is the most vital element for hemoglobin and myoglobin development in fish as well as it also plays a fundamental role for the growth of aquatic organisms. Unfortunately, increased industrial effluents polluted the natural ecosystem and it enhanced at momentous contamination stage (Hussain et al., 2011). Nickel, a grey-listed metal (Mason, 1996), is an element of less importance for numerous animal species (Phipps et al., 2002), and if it is existed in large deposits, then the endurance, augmentation, behavior, and reproduction of aquatic animals are affected (Wong et al., 1993).

The insecure concentrations of heavy metals in our riverine systems and their negative effects on fish require conducting this research project to observe the toxic impacts of iron and nickel mixture on the most cultured fish species of Pakistan viz. Catla catla, Labeo rohita, Cirrhina mrigala, Ctenopharyngodon idella and Hypophthalmichthys molitrix.

1 Results and Discussion
1.1 Acute toxicity of metals mixture to the fish 
Large deposits of heavy metals found in the earth’s crust, air, water and food impose negative impacts on aquatic life (Naz and Javed, 2012) as these metals cause serious health problems in animal and humans, directly as well as indirectly (Azmat and Javed, 2011). However, the individual metals do not induce toxicity in the natural aquatic environment but they become hazardous when present in form of mixture (Naz et al., 2012).

Testing of five fish species for their 96-hr LC50 and lethal concentrations of metal mixture with 95% confidence interval are shown in Table 1. The differences among all the five fish species, for their ability to tolerate metal mixture in terms of 96-hr LC50 and lethal concentrations, varied significantly. Regarding overall sensitivity of five fish species, Hypophthalmichthys molitrix were significantly more sensitive to metals mixture, followed by that of Labeo rohita, Ctenopharyngodon idella, Catla catla and Cirrhina mrigala. Acute (LC50) toxicity trails were performed on major carps (Catla catla, Labeo rohita and Cirrhina mrigala) exposed to metals mixture (Fe+Ni+Pb+Zn+Mn) by Naz and Javed (2012). They found that, on observing overall sensitivity of three fish species, Labeo rohita depicted significantly least sensitivity to metal mixtures with mean LC50 and lethal concentrations of 81.73±12.73 and 128.80 ±19.95 mg/L, respectively. Hua and Qixing (2009) demonstrated an experiment to predict the single and joint effects of metals (Cd and Zn) on grass carp (Ctenopharyngodon idella). The concluded on the basis of LC50 (96-hr) values that acute toxicity of zinc was significantly lower than cadmium as the 96-hr LC50 of cadmium and zinc were 26.86 mg/L and 33.14 mg/L, respectively. Acute methods are utilized to compare the ability of species having numerous developmental stages and diversified phylogenetic positions, when they are exposed to toxicants (Kazlauskiene et al., 2003; Abdullah and Javed, 2006). However, in nature, the toxicants and their mixtures have constant effect on various species during continuing exposure of their negligible concentration.

 Table 1 Responses of five fish species for their 96-hr LC50 and lethal concentrations (mg/L) of metals mixture (Fe+Ni)

The relationships between LC50 and lethal concentrations of five fish species against metal mixture were computed also by regression analysis. There existed highly significant correlations between 96-hr LC50 and lethal concentrations of all the four fish species against metal mixture except for Ctenopharyngodon idella (Table 2). The higher values of coefficient of determination (R2) for all the equations computed for all the fish species predict high reliability of theses regression models. On exposing three fish species viz. Catla catla, Labeo rohita and Cirrhina mrigala  to 96-hr LC50 and lethal concentrations of metals, significantly direct relationships were examined between them (Azmat, 2011).

Table 2 Relationships between 96-hr LC50 and lethal concentrations (mg/L) of mixture for five fish species

1.2 Uptake and accumulation of metals in fish body during acute exposure of mixture 
Studies on metals bioaccumulation can present data to investigate aquatic toxicants. Hence, the routes of entry of different toxicants to different tissues/organs, their amount ingested and their retention level in each tissue can be evaluated. The background iron and nickel concentrations in body organs of 90-day Catla catla, Labeo rohita, Cirrhina mrigala, Ctenopharyngodon idella and Hypophthalmichthys molitrix, before metal mixture exposure were determined and  their values are  presented in Table 3. However, during acute toxicity trails (96-hr LC50 and lethal concentrations) the accumulation of both metals in form of mixture in body organs of five fish species increased significantly (Table 4). Metals accumulation in kidney, liver, fins, bones, muscles and gills occurs, when different metals enter in the fish body by means of water and feed intakes (Rauf et al., 2009). The 96-hr LC50 exposure of Fe+Ni mixture caused significantly maximum mean accumulation of iron (258.62±279.42 µgg-1) in body organs of Cirrhina mrigala, followed by that of Hypophthalmichthys molitrix, Labeo rohita, Ctenopharyngodon idella and Catla catla (Table 4). The uptake of essential and non-essential metals as well as their accumulation by the fish is related. In contrast to it, the metals accumulation patterns and their toxic effects in several fish species fluctuate significantly (Luoma and Rainbow, 2005; Abdullah et al., 2011). Activities of fish like feeding and swimming drastically reduce and they grew weaker as the exposure time was prolonged. This is particularly noticed in test organisms in higher concentrations.

Table 3 Metal concentrations (µgg-1) in control fish used during acute toxicity trials 

 Table 4 Accumulation patterns of metals (µgg-1) in fish organs during 96-hr LC50 and lethal concentrations exposure of metal mixture (Fe+Ni)

Mean iron accumulation in five fish species was significantly higher in kidney (335.05±302.02 µgg-1), followed by that in gills, liver, skin, bones, muscle and fins. Due to waterborne and dietary exposure of metal mixture (Cu+Cd+Zn+Ni+Co) to fish, the kidney, gills and liver demonstrated significantly higher accumulation of all metals (Javed and Abdullah, 2004). Nickel accumulation was significantly maximum (143.90±136.92 µgg-1)  in Cirrhina mrigala and that of minimum was exhibited by Labeo rohita. The effects of toxicants in terms of level of toxicity and accumulation varied from species to species (Luoma and Rainbow, 2005). Gupta and Srivastava (2006) investigated the accumulation level of zinc in Channa Punctatus exposed to three concentrations of zinc (10, 15, and 25 mg/L). They found significant increase of this metal in fish body. Fish kidney showed significantly highest tendency for the accumulation of 194.44±110.98 µgg-1 nickel while fish bones exhibited the least tendency for these accumulations. An exposure of metals mixture (Cu+Cd+Zn+Ni+Co) to major carps caused significantly higher accumulation of theses metals in their body. However, these accumulation were significantly minimum in fish bones (Javed, 2012 b).

During lethal exposure of Fe+Ni mixture, Cirrhina mrigala accumulated significantly higher concentrations of both iron and nickel in its body. Among the fish organs, kidney showed significantly higher tendency for the accumulation of both iron (517.20±362.62 µgg-1) and nickel (323.57±136.58 µgg-1). Azmat et al. (2012) pointed out kidney as an appropriate indicator of metal contamination in major carps. Water-borne metals can be elated to various organs to stimulate cellular and histopathological amendments that lead to genetic alteration in animals (Tkatcheva et al., 2000). Metals bio-accumulation is dependent upon their route of uptake, concentration, storage, availability and mechanisms of excretion in animals (Vijver et al., 2004). The exposure of this mixture resulted in significantly higher iron accumulation in fish body than that of nickel. Palaniappan and Karthikeryan (2009) conducted a study to investigate the bio-accumulation as well as the depuration of chromium, individually or in mixture form with nickel in the body organs of Cirrhinus mrigala. Their results indicated that the level of accumulation of chromium in all fish organs was significantly lower than that of nickel. Synergistic relationship was developed between these metals as the mixture of Ni+Cr was more toxic to the fish than the effect of these metals alone.

1.3 Physico-chemical parameters
Due to various types of biological and physical pollutants that come out from several industrial and agricultural sources has greatly influenced the water quality (Andhale and Zambare, 2011). The data on physico-chemical parameters of the test media estimated during these tests and control treatments revealed that the mean values of total ammonia, electrical conductivity and sodium were higher than that of control media. However, the treated fish mediums had lower concentrations of dissolved oxygen than mediums used for control fish. The concentrations of calcium, potassium and magnesium in both mediums used for treated and control fish remained almost same during acute toxicity trails (Table 5). Dissolved oxygen of contents of the media decreased significantly due to enhanced excretion of ammonia by the fish. Naz et al. (2012) investigated during their study on the acute toxicity of metals mixture to fish (Catla catla, Labeo rohita, Cirrhina mrigala, Ctenopharyngoden idella and Hypophthalmichthys molitrix) that increase in ammonia excretion caused significant decrease in dissolved oxygen contents of the water media.

Table 5 Mean values for physico-chemical variables of the test and control media

2 Conclusion
Regarding overall sensitivity of fish species, Labeo rohita were significantly least sensitive towards LC50 and lethal concentrations of metals mixture. While concerning overall bioaccumulation patterns of iron and nickel in fish body, significant differences were observed for accumulation of metals. However, significantly higher accumulation was shown by iron as compared to that of nickel. Fish kidney appeared as an organ that showed significantly higher tendency of the accumulation of both nickel and iron.

3 Materials and Method
Fingerlings of Catla catla, Labeo rohita, Cirrhina mrigala, Ctenopharyngoden idella and Hypophthalmichthys molitrix of average weights of 3.28 g, 5.60 g, 4.46 g, 4.03 g, 3.85 g, fork lengths of 56.04 mm, 74.05 mm, 71.88 mm, 69.31 mm and 64.06 mm and total lengths of 65.84 mm, 84.11 mm, 81.51 mm, 80.00 mm and 74.91 mm, respectively were collected from local Fish Seed Hatchery, Faisalabad, Pakistan. Fish species were kept under laboratory conditions for 14 days for acclimation prior to start of this experiment. The laboratory photoperiod was 12 hours by using fluorescent light. Fish species were fed with pelleted feed having 35% digestible protein and 2.90 Kcal/g digestible energy and then 70% water was renewed every day. Feeding was hovering 24 hours earlier during this mortality experiment for all fish species. Glass aquaria of 60 liter water capacity were used in this experiment. Fresh air was supplied to the each aquaria through air pump fitted with capillary system. Pure chloride compounds of iron and nickel (Aldrich, USA) were used as the metal toxicant in this study. Desired concentration of metal mixture was prepared by dissolving an appropriate volume of stock solution in tap water. Fish species were exposed to metal mixture concentration of 0 mg/L, 5 mg/L, 10 mg/L, 20 mg/L, 25 mg/L, 30 mg/L, 35 mg/L, 35 mg/L, 40 mg/L, 45 mg/L,  50 mg/L, 55 mg/L, 60 mg/L, 65 mg/L, 70 mg/L, 75 mg/L, 80 mg/L, 85 mg/L, 90 mg/L, 95 mg/L, 105 mg/L, 120 mg/L, 125 mg/L, 130 mg/L and 135 mg/L for 96 hours for determination of their tolerance limits. The concentrations were maintained within 3.5 hours and full toxicant concentrations in 7 hours. Each fish species was experienced, separately, for this acute toxicity experiment against binary mixture of iron and nickel at constant temperature (300C) total hardness (225 mg/L) and pH (7). Fish mortality observations were made twice a day. The metal mixture (Fe+Ni ) concentrations for each fish species were started from zero with an increment of 0.05 mg/L and 5 mg/L for low and high concentrations, respectively  for LC50 and lethal concentrations. No mortality of fish was observed in control media. Fish mortality data obtained against each concentration during 96 hours test duration. Each test dose was tested in triplicate. The acute toxicity bioassay method based on standard method was determined to evaluated 96-hr and LC50 and lethal concentrations of metal mixture for five fish species.  The 96-hr and LC50 and lethal concentrations of Fe+Ni mixture for each fish species as calculated by using probit analysis method (Ezeonyejiaku and Obiakora, 2011). Regression analyses were performed to find out relationship between LC50 and lethal concentrations for each fish species.

The metals in fish body organs were also determined after acute toxicity tests by following the method of S.M.E.W.W. (1989). The fish were dissected and different organs viz. gills, liver, kidney, fines, bones, muscles and skin were taken from the experimental and metal free (control) aquaria separately and all the organs were washed with distilled water. Fish organs were digested in HNO3 and HClO4 (3:1 V/V) by following S.M.E.W.W. (1989). The final acid digested extract was analyzed for metal mixture (Fe+Ni) by using Atomic Absorption Spectrophotometer (Analyst-400, Perkin Elmer).

Water temperature, pH and dissolved oxygen of the test media were determined twice a day by using digital meters, viz. HANNA HI-8053, HI-8733, HI-8520, HI-9146, respectively. However, total hardness, total ammonia, chlorides, sodium and potassium concentrations in each test medium were determined by the methods ofA.P.H.A. (1998). Water temperature was maintained at 30 ℃ by using automatic heaters. The pH of the test media was maintained by adding NaOH and HCl to increase and decrease pH, respectively. In order to maintain the total hardness of water, salts of MgSO4 and CaSO4 were added to increase the hardness while EDTA was used to decrease the water hardness. Data obtained from this acute toxicity tests were analyzed and all the results were expressed as mean±S.D. The results were evaluated using Analysis of variances and Tukey‘s/ Student Newnan-Keul tests (Steel et al., 1996).

The author is extremely thankful to the “Pakistan Science Foundation” for the endowment of funds under the research project No.85 (Env) to complete this work as a part of PhD research.

APHA., 1998, Standard methods for the examination of water and wastewater, 20th edition, American Public Health Association, New York, USA
Abdullah S., and Javed M., 2006, Studies on 96-hr LC50 and lethal toxicity of metals to the fish, Cirrhina mrigala, Pak. J. Agric. Sci., 43: 180-185
Abdullah S., Javed M., Yaqub S., and Ahmad A., 2011, Metal bioaccumulation patterns in major carps, Int. J. Agri. Biol., 13: 756-760
Andhale A V., and Zambare SP., 2011, Effect of nickel induced biochemical alterations in fresh water bivalve, Lammellidens marginalis, J. Ecobiot., 3: 18-24
Azmat H., and Javed M., 2011, Acute toxicity of chromium to Catla catla, Labeo rohita and Cirrhina mrigala under laboratory conditions, Int. J. Agri. Biol., 13: 961-965
Azmat H., 2011, Studies on 96-hr LC50 and lethal responses of major carps in relation to their growth and bioaccumulation of waterborne metals, Ph.D. Thesis, Department of Zoology and Fisheries, University Agriculture, Faisalabad, Pakistan, pp. 114
Azmat H., Javed M., and Jabeen G., 2012, Acute toxicity of aluminium to the fish (Catla catla, Labeo rohita and Cirrhina mrigala), Pak. Vet. J., 31: 85-87
Basa Siraj P., and Usha Rani A., 2003, Cadmium induced Oreochromis mossambicus (Tilapia), Ecotox. Environ. Saf., 56: 218-221 http://dx.doi.org/10.1016/S0147-6513(03)00028-9 
Bervoets L., Blust R., and Verheyen R., 2001, Accumulation of metals in the tissues of three spined stickleback (Gasterosteus aculeatus) from natural freshwaters, Ecotox. Environ. Saf., 48: 117-127 http://dx.doi.org/10.1006/eesa.2000.2010
PMid: 11161686 
Birungi Z., Masola B., Zaranyika M.F., Naigaga I., and Marshall B., 2007, Active biomonitoring of trace heavy metals using fish (Oreochromis niloticus) as bioindicator species. The case of Nakivubo wetland along Lake Victoria, Phy. Chem. Earth., 32: 1350-1358 http://dx.doi.org/10.1016/j.pce.2007.07.034 
Ebrahimpoure M., Alipour H., and Rakhshah S., 2010, Influence of water hardness on acute toxicity of copper and zinc on fish, Toxicol. Indus. Health, 26: 361-365 http://dx.doi.org/10.1177/0748233710369123 PMid: 20504831 
Ezeonyejiaku C.D., and Obiakora M.O., 2011, Toxicological study of single action of Znic on Tilapia specie (Tilapia nilotica), J. Anim. Feed Res., 1: 139-143
Farombi E.O., Adelowo O.A., and Ajimoko R.K., 2007, Biomarkers of oxidative stress and heavy metal levels as indicator of environmental pollution in African Cat fish (Clarias gariepinus) from Nigeria ogun River, Int. J. Environ. Res. Public Health, 4: 158-165 http://dx.doi.org/10.3390/ijerph2007040011 PMid: 17617680 
Fernandes C., Fontainhas-Fernandes A., Peixoto F., and Salgado MA., 2007, Bioaccumulation of heavy metals in Lisa saliens from the Esmoriz-Paramos coastal lagoon, Portugal. Ecotoxicol. Environ. Saf., 66: 426–431
http://dx.doi.org/10.1016/j.ecoenv.2006.02.007 PMid: 16620977 
Gupta P., and Srivastava N., 2006, Effects of sub lethal concentrations of zinc histological changes and bioaccumulation of zinc by kidney of fish, Channa punctatus (Bloch), J. Environ. Biol., 27: 211-215
Hua T., and Qixing Z., 2009, Joint toxic effect of Cd and Zn on grass carp (Ctenopharyngodon idella) and SOD activity, Acta Sci. Curricum., 29: 312-316
Hussain S.M., Javed M., Javid A., Javid T., and Hussain N., 2011, Growth responses of Catla catla, Labeo rohita and Cirrhina mrigala during chronic exposure of iron, Pak . J. Agri. Sci., 48: 225-230 
Jabeen G., Javed M., and Azmat H., 2012, Assessment of heavy metals in the fish collected from the river ravi, Pakistan. Pak. Vet. J., 32: 107-111
Javed M., and Abdullah S., 2004, Studies on growth and bio-energetics of fish under heavy metal toxicity, 2nd Annual report of PSF project No. Env 62, pp: 66 
Javed M., 2012a, Tissue-specific bio-accumulation of metals in fish during chronic waterborne and dietary exposures, Pak. Vet. J., 32: 567-570
Javed M., 2012b, Effects of metals mixture on the growth and their bioaccumulation in juvenile major carps, Int. J. Agric. Biol., 14: 477-480
Javed M., and Abdullah S., 2006, Studies on the acute and lethal toxicities of iron and nickel to fish, Pakistan J. Biol. Sci., 9: 330-335 http://dx.doi.org/10.3923/pjbs.2006.330.335
Kazlauskiene N., Svecevicius G., and Vosyliene M.Z., 2003, The use of rainbow trout (Oncorhynchus mykiss) as a test-object for evaluation of the water quality polluted with heavy metals. Heavy metals in the environment: An integrated approach, Vilnius, 12(3): 231-234
Khare S., and Singh S., 2002, Histopathological lesions induced by copper sulphate and lead nitrate in the gills of fresh water fish Nandus, J. Ecotoxicol. Environ. Monit., 12: 105-111
Luoma S S., and Rainbow P.S., 2005, Why is metal bioaccumulation so variable? Biodynamics as a unifying concept, Environmental Science and Technology, 39(7): 1921-1931 http://dx.doi.org/10.1021/es048947e PMid: 15871220 
Mason C.F., 1996, Biology of freshwater pollution, 3rd Ed, Longman, London, pp.1-4
Naz S., and Javed M., 2012, Acute toxicity of metals mixtures for fish, Catla catla, Labeo rohita and Cirrhina mrigala, Pak. J. Agri. Sci., 49: 387-391 
Naz S., Javed M., Tahir A., and Azmat H., 2012, Impact of physico-chemical variables of test media on growth performance of metal stressed major carps, Pak. J. Zool., 44: 1291-1296 
Palaniappan P.L., and Karthikeyan S., 2009, Bioaccumulation and depuration of chromium in the selected organs and whole body tissues of freshwater fish, Cirrhinus mrigala individually and in binary solutions with nickel, J. Environ. Sci., 21: 229-236 http://dx.doi.org/10.1016/S1001-0742(08)62256-1 
Phipps T., Tank S.L., Wirtz J., Brewer L., Coyner A., Ortego LS., and Fairbrother A., 2002, Essentiality of nickel and homeostatic mechanisms for its regulation in terrestrial organisms, Environ. Rev., 10: 209-261 http://dx.doi.org/10.1139/a02-009
Rauf A., Javed M., Ubaidullah M., and Abdullah S., 2009, Heavy metal levels in three major carps (Catla catla, Labeo rohita, Cirrhina mrigala) from the river Ravi, Pakistan. Pak. Vet. J., 29: 24-26
SMEWW., 1989, Standard methods for the examination of water and wastewater, 17th ed., Washington, DC.
Steel R.G.D., Torrie J.H., and Dinkkey D.A., 1996, Principles and procedure of statistics, 3rd ed., McGraw Hill Book Co., Singapore, 627P.
Tkatcheva V., Holopainen I.J., and Hyvarinen H., 2000, Heavy metals in perch (Perca fluviatilis) from the Kostomuksha region (North-Western Karelia, Russia), Boreal Environ Res., 5: 209-220 
Vijver M.G.,  Van Gestel C.A.M.,  Lanno R.P.,  Van Straalen N.M., and Peijnenburg W.J.G.M., 2004, Internal metal sequestration and its ecotoxicological relevance: A review, Environ. Sci. Tec., 38: 4705-4712 http://dx.doi.org/10.1021/es040354g
PMid: 15487776 
Vinodhini R., and Narayanan M., 2008, Bioaccumulation of heavy metals in organs of fresh water fish, Cyprinus carpio (Common carp), Int. J. Environ. Sci. Tech., 5: 179-182
Wong C.K., Chu K.H., Tang K.W., Tam T.W., and Wong L.J., 1993, Effects of chromium, copper and nickel on survival and feeding behaviour of Metapenaeus ensis larvae and post larvae (Decapoda: Penaeidae), Marine Environ Res., 36: 63-78

Bioscience Methods
• Volume 4
View Options
. PDF(225KB)
Associated material
. Readers' comments
Other articles by authors
pornliz suckporn porndick pornstereo . Saima Naz
. Muhammad Javed
Related articles
. Acute toxicity
. Bioaccumulation
. Metal mixture
. Fish
. Fe
. Ni
. Email to a friend
. Post a comment