Research Report

Acute Toxicity and Haematology of Clarias gariepinus Exposed to Selenium  

D.O. Odedeyi , K.E. Odo
Department of Animal and Environmental Biology, Faculty of Science, Adekunle Ajasin University, Akungba-Akoko, Ondo State, Nigeria
Author    Correspondence author
International Journal of Aquaculture, 2017, Vol. 7, No. 9   doi: 10.5376/ija.2017.07.0009
Received: 22 May, 2017    Accepted: 15 Jun., 2017    Published: 30 Jun., 2017
© 2017 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.
Preferred citation for this article:

Odedeyi D.O., and Odo K.E., 2017, Acute toxicity and haematology of Clarias gariepinus exposed to selenium, International Journal of Aquaculture, 7(9): 64-70 (doi: 10.5376/ija.2017.07.0009)

Abstract

The acute toxicity and haematological effect of selenium was investigated on Clarias gariepinus juvenile. 180 healthy C. gariepinus juveniles with mean weight of 7.4 ± 0.64 g and length of 11.2 ± 0.88 cm were exposed to different concentrations (0, 2, 3, 4, 5 and 6 mg/l) of selenium under a static method of bioassay for 96 hours. The mortality rate of the experimental fish increased with increase in concentration of the selenium. The 24, 48, 72 and 96 hours LC50 were estimated to be 8.49, 6.36, 4.80 and 3.39 mg/l respectively which was analysed using probit method. The dissolved oxygen of the culture media was significantly lower p < 0.05 in the treatments when compared to the control. The blood parameters: Pack Cell Volume (PCV), Red Blood Cell (RBC), White Blood Cell (WBC) and Haemoglobin (Hb) showed decrease from lowest concentration (2 mg/l) to highest concentration (6 mg/l). There were variations in the derived haematological indices of mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC). In conclusion, it was observed that selenium at high concentration is toxic and caused a successive population decline of C. gariepinus. Fish farmers should as much as possible locate farms from likely source of toxicants.

Keywords
Selenium; Clarias gariepinus; LC50; Haematology

1 Introduction

Water pollution has become a global problem and rapid industrialization is one of the main causes of aquatic pollution because most of their effluents are being discharged in the aquatic environment. Heavy metal pollution is one of the most important environmental problems today. Contamination of fresh water with a wide range of pollutants has become a matter of concern over last few decades (Vutukuru, 2005). Modern industries are to a large extent, responsible for contamination of the environment. Nriagu and Pacyna (1988) reported that industrial wastes contain various types of toxic metals. These include: Hg (mercury), Cr (chromium), Pb (lead) Se (selenium), Zn (zinc), Cu (copper), Ni (nickel), Cd (cadmium), As (arsenic), Sn (tin), etc. Heavy metals are high priority pollutants because of their relative high toxicity and persistent. Though, many metals play a vital role in the physiological processes of plants, animals and humans, yet excess concentration of metals is harmful (Ololade and Oginni, 2010). The effect of heavy metals on aquatic organisms is currently attracting widespread attention, particularly in studies related to pollution (Khalid, 2011). Selenium is an essential trace element which is required in animal diet, including fish for normal growth and physiological function of animal (Abbas, 2009) it is also required for maintenance of homeostatic functions at trace concentrations (Monterio et al., 2009a). However, selenium can bio accumulates and become toxic. It is used in a number of industrial and manufacturing processes including photoelectric cells, steel manufacture, anti-dandruff shampoos, fungicide, and glass manufacturing (Nagpal, 2001). Selenides (-2) are usually present as organic compounds (Bowie et al., 1996), such as selenomethionine and selenocysteine (Combs and Combs, 1986), and are physically and chemically similar to sulphides (Banks, 1997). Major anthropogenic sources of Se include fossil fuel combustion, mining, and agricultural drainwater (Haygarth 1994; Lemly, 1999). Other anthropogenic sources that may increase selenium contamination are open pit phosphate mining, wetlands constructed to treat Se-laden wastewater, and feedlot waste (Lemly, 1999). Upon entering an aquatic ecosystem, Selenium may be absorbed or ingested by aquatic organisms, bind to particulate matter, or stay free in solution (Lemly and Smith, 1987). African catfish (Clarias gariepinus) is appreciated by large population (Prusynski, 2003). It is an excellent species for aquaculture as it is omnivorous, grows fast, and tolerates relatively poor water quality (Rad et al., 2003). Several investigations have been carried out on various toxicants with Clarias sp. (Aguigwo, 1998; Maheswaran et al., 2008). Changes in several haematological variables are recognized as indicators of metal exposure (Cyriac et al., 1989). Blood parameters has been used as an indicator of stress in fish exposed to different toxicants such as heavy metals and industrial effluents. In fish, exposure to chemical pollutants can induce either increase or decrease in haematological levels (Mehjbeen and Nazura, 2012). The haematological effects of various metals such as Hg, Cu, Cd and Pb on Clarias sp have been reported in various studies. Oshode et al., (2008) reported that observation of haematological parameters allows the most rapid detection of changes in fish. Disrupted haematological patterns appear very quickly and precede changes in fish behaviour and visible lesions. The rapidity of toxic effects, exerted by heavy metals, is related to the blood’s transport function, with the blood distributing the metals to all the body parts. Literatures has reviewed that there are no much work on the haematological effects of selenium on C. gariepinus. Therefore this present study was to investigate the acute toxicity of selenium and its effect on blood parameters of C. gariepinus juvenile.

 

2 Materials and Methods

Juveniles of African catfish (C. gariepinus) with average weight of 7.4 ± 0.64 g were used for the study. 180 healthy fish which were purchased from a reputable fish farm were acclimatized (10 each) in eighty litres plastic container filled with forty litres of tap water each for a period of 4 weeks to the laboratory condition. During this period of acclimatization, the fish were fed with commercial pellets twice daily at 3% body weight and water was changed every other day. The fish were not fed 48 hours prior to experiment in order to minimise waste from fish.

 

Toxicant stock solution of the tested metal, a pure chemical: sodium bi- selenite was prepared by dissolving 5 g of reagent equivalent to 1 g of selenium in 1000 ml water at concentration of 1000 mg/l. From the stock solutions, different concentrations required were prepared after a range – finding test using a screening procedure. The concentrations prepared for the experiment were: 2, 3, 4, 5 and 6 mg/l based on literature guidance (Burba 1999; Vinodhini and Narayanan, 2008). This was prepared 24 hours before the experiment in other for the chemical to properly dissolve.

 

Water quality monitoring was done every 24 hours throughout the period of the experiment. The pH, conductivity, dissolved oxygen, and temperature was done with the use of HI-769828 multi-parameter water analysis probe. Ammonia, nitrate and nitrite test was done with the use of NT LABS pond water multiparameter test kit.

 

Blood samples were collected from both the control and experimental fishes that survived the 96 h toxicant exposure period. The blood samples were taken by puncturing posterior caudal vein and collected into ethylenediaminetetraacetate (EDTA) bottle (Schmitt et al., 1999). Automated haematology analyser mindray Bc 300 plus was used to determine haematological parameter. The derived haematological indices of mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC) were calculated using standard formulae as described by Jain (1986): MCV was calculated in fentoliters = PCV/RBC x 10; MCH was calculated in picograms = Hb/RBC x 10; and MCHC = (Hb in 100 mg blood / Hct) x 100.

 

Data obtained were subjected to one-way analysis of variance (ANOVA) test and the means from the various treatments were compared for significant differences (P>0.05) using Duncan’s multiple range tests. Values were expressed as mean ± S.E. 96 hours LC50 was determined using probit analysis (Finney, 1971) and simple graphical method.

 

3 Results

3.1 Trends in mortality and physicochemical parameters

Time to death was shorter in the higher concentrations (Figure 1). At the first 12 hours, there were no noticeable effect on the test organisms even at higher concentrations. Few mortality were recorded at the first 24 hours of the toxicant introduction but at 72-96 hours, mortality rate increases speedily. The mortality rate of the experimental fish increased with increase in concentration of the toxicant. The 24, 48, 72 and 96 hours LC50 was estimated to be 8.49, 6.36, 4.80 and 3.39 mg/l respectively which was analysed using probit analysis.

 

 

Figure 1 Trend in fish mortality with duration of exposure to selenium

 

3.2 Haematological variables

Table 1 showed the mean value of the haematology. PCV of untreated group is significantly higher (48.33±0.58) than the treatment groups while that of the treatments decreases (22.67, 21.67, 19.00, 17.00 and 12.50) with increase in concentration of selenium except for treatment 1 which is slightly higher than treatment 2 but showed no statistical differences. The WBC of the treated groups were significantly lower than the control. No significant difference between treatments 1 and 2. Also,no significant difference between treatments 3, 4, and 5. The haemoglobin concentration was highest (25.71) in the unexposed fish while it was least (4.96) in the group exposed to highest concentration of selenium (6 mg/l). There was a slight decrease with increase in concentration of the treated groups while the unexposed fish had the highest RBC count. There were great variations in the values of MCV, MCH and MCHC. Mean corpuscular volume (MCV) of treatments 4 and 5 were significantly higher (p ˃ 0.05) compared to control group. Treatment 5 had the highest mean corpuscular haemoglobin (MCH) value while mean corpuscular haemoglobin concentration (MCHC) was higher in the control than treatment groups.

 

 

Table 1 Haematological parameters of C. gariepinus

Note: Mean with different superscripts are significantly different

 

3.3 Water parameters

In Table 2, dissolved oxygen decreased with increase in concentration of selenium. However, all other parameters showed no significant difference.

 

 

Table 2 Water quality parameters of culture system of C. gariepinus observed over period of 96 hours

Note: Mean with different superscripts are significantly different

 

4 Discussions

The present study shows that C. gariepinus juvenile are susceptible to selenium toxicity; the LC50 reduces with increase in duration of exposure. Also, the higher the concentration of selenium, the higher the mortality rate (Figure 2). The 96 hours LC50 of selenium in this study (3.39 mg/l) has a close range with the 96 hours LC50 of selenium (2.5 mg/l) exposed to Channa punctatus (Blouch) (Avinashe and Patil, 2011). 96 hours LC50 of 4.32mg/l was also recorded when Oreochromis species was exposed to selenium concentration (Hossam et al., 2009) The mortality recorded in the study might be a consequence of stress induced by selenium on the immune system of C. gariepinus which probably slow toxic progress and resulted in acute toxic response.

 

 

Figure 2 96 hours LC50 of Clarias gariepinus juvenile exposed to selenium

 

Blood parameters have been used as sensitive indicator of stress in fish exposed to different water pollutants and toxicants, such as metals, biocides, pesticides and industrial effluents (Dharam et al., 2008). The study of haematological picture are frequently utilised for the detection of pathological changes in different stress conditions such as exposure to heavy metals (Nussey et al., 1995). Jayapakash and Shettu (2013) reported after the exposure of Channa punctatus to deltamethrin that anaemia might have led to a fall in the red blood cell count, haemoglobin and pack cell volume. In the present study, PCV% value, Hb%, and RBC count of C. gariepinus exposed to selenium decreased significantly P < 0.05 when compared to the control group. This reduction could be an indication of anaemia condition caused by the exposure of experimental fish to selenium in water. The observed decrease in the haemoglobin and pack cell volume value in the fish could also be as a result of erythrocyte lysing. The decreased haemoglobin concentration also signifies that the fish ability to provide sufficient oxygen to the tissue is restricted considerably and this will result in decreased physical activity (Nussey et al., 1995). Several studies have been reported on the reduction of haematological parameters of fish exposed to heavy metals (Dhiaram et al., 2008; Ololade and Oginni, 2010; Khalid, 2011). A decrease in the haematological values of common carp fish when exposed to nickel, Khalid (2011). Ololade and Oginni (2010) also had similar report when African cat fish was exposed to nickel. Pamile et al. (1991) explained that reduction in haemoglobin content in fish exposed to toxicant could be due to the inhibiting effect of the toxic substance in the enzyme system responsible for synthesis of haemoglobin.

 

The reduction in WBC count of the treatment groups that was observed in this study agreed with the finding of Adeyemo et al. (2007) following the exposure of C. gariepinus to lead nitrate. This result is also similar to the findings of Olanike (2007) and Witeska (2003) that attributed this to the release of epinephrine during stress which causes a decrease in leucocyte count, and also shows the weakening of the immune system.

 

There were variations in the values of blood indices MCV, MCH and MCHC. Mean corpuscular volume (MCV) of treatment 4 and 5 were significantly higher (p ˃ 0.05) compared to control group while mean corpuscular haemoglobin (MCH) also increased significantly in fish exposed to highest concentration of selenium. This result is similar to the finding of Adeyemo et al. (2007) that exposed C. gariepinus to lead nitrare. It also agreed with the work of Shah, (2006) following a short term exposure of tench (Tinca tinca) to lead. Mean corpuscular haemoglobin concentration (MCHC) was significantly higher in the control than treatment group. MCHC is a red blood cell morphological index reflecting the haemoglobin concentration, the observed decrease in this parameter may indicate that the haemoglobin concentration in the unexposed fish was higher than in the selenium exposed fish and this may further suggest impaired haemoglobin synthesis in the treated fish. These alterations were attributed to direct or feedback responses of structural damage to RBC membranes resulting in haemolysis and impairment in haemoglobin synthesis, stress-related release of RBCs from the spleen and hypoxia, induced by exposure to lead (Shah, 2006).

 

Water parameters such as pH, turbidity, alkalinity, dissolved oxygen, temperature, and conductivity were influenced by the rate of pollutant entering aquatic environment (Fagbenro, 2002; Olufayo, 2009). The dissolved oxygen is significantly lower (P < 0.05) in the test medium of the treatment groups. This could be that the oxygen molecules is been degraded by selenium. This study agreed with the study carried out by Ololade and Oginni (2010) when C. gariepinus was exposed to nickel. No significant difference was recorded in pH.

 

Selenium has been examined to have toxic effect on C. gariepinus juveniles. It is therefore recommended that industries should install waste treatment plant, with a view to properly treat waste water before discharging them into aquatic environment.

 

References

Abba H.H.H., and Authman M.M.N., 2009, Effects of accumulated selenium on Some physiological parameters and oxidative stress indicators in Tilapia fish (Oreochromis spp.). Eurasian Journal of Agriculture and Environmental Science, 5: 219-225

 

Adeyemo O., Ajani F., and Ajiboye O., 2007, Acute toxicity and blood profile of adult Clarias gariepinus exposed to lead nitrate. The Internet Journal of Hematology, 4 (2)

 

Aguigwo J.N, 1998, Studies on acute toxicity of Cassava leaf extracts on African catfish Clarias angullaris, Journal of Aquatic Science, 13: 29-32

 

Avinashe A.M., and Patil G.P., 2011, Histopathological lesions in liver of the fresh water fish, Channa punctate (Bloch) exposed to selenium dioxide, Vidyabharati International Interdisciplinary Research Journal, 1(1): 11-15

 

Banks A., 1997, Selenium. In: Lagowski J, editor. Macmillan Encyclopedia of Chemistry. New York: Simon and Schuster Macmillan, p 1334

 

Bowie G., Sanders J., Riedel G., Gilmour C., Breitburg D., Cutter G., and Porcella D., 1996, Assessing selenium cycling and accumulation in aquatic ecosystems, Water, Air and Soil Pollution, 90:93-104

https://doi.org/10.1007/BF00619271

 

Combs G., and Combs S., 1986, The role of selenium in nutrition. Orlando: Academic Press, Inc. 532 p.

 

Cyriac P.J., Antony A., and Nambison P.N.K., 1989, Haemoglobin and haematocrit values in the fish Oreochromis mossambicus (Peters) after short term exposure to copper and mercury. Bulletin of Environmental Contamination and Toxicology, 43:315-320

https://doi.org/10.1007/BF01701764

PMid:2775899

 

Fagbenro O.A., 2002, Tilapia: Fish for Thought, Inaugural Lecture Series 32. Delivered at Federal University of Technology, Akure, P. 77

 

Finney D.J., 1971, Probit Analysis. 3rd Edition. Cambidge University Press, NY, P. 328

 

Haygarth P., 1994, Global importance and global cycling of selenium. In: Frankenberger W, Jr., Benson S, editors. Selenium In The Environment. New York: Marcel Dekker Inc., p 1-28

 

Jayaprakash C., and Shettu N., 2013, Chages in the haematology of fresh waterfish, Channa punctatus (Bloch) exposed to the toxicity of deltamethrin. Journal of Chemical and Pharmaceutical Research, 5(6): 178-183

 

Javed M., and Usmani N., 2012, Haematological indices of Channa punctatus as an indicator of heavy metal pollution in waste water aquaculture pond, African Journal of Biotechnology Vol. 12(5), pp. 520-525

 

Khalid A.A., 2011, Impact of nickel on haematological parameters and behavioural changes in Cyprinus carpio. African journal of Biotechnology Volume 10(63), pp. 13860-13866

https://doi.org/10.5897/AJB11.1893

 

Kori-Siakpere O., Egor V.E., 1999, Haematological characteristics of African mudfish. Clarias buthupogon. (Pisces: Clariidae). Bulletin of Science and Association of Niger, 21: 177-185

 

Lemly A., and Smith G., 1987, Aquatic cycling of selenium: Implications for fish and wildlife. Washington, DC: US Fish and Wildlife Service, Report nr 12. 10

 

Lemly A., 1999, Selenium impacts on fish: an insidious time bomb. Human and Ecological Risk Assessment, 5(6):1139-1151

https://doi.org/10.1080/10807039.1999.10518883

 

Lemly A., 2002, Symptoms and implications of selenium toxicity in fish: the Belews Lake case example. Aquatic Toxicology, 57:39-49

https://doi.org/10.1016/S0166-445X(01)00264-8

 

Maheswaran R., Devapanl A., Muralidharan S., Velmurugan B., Ignaeimuthu S., 2008, Haematological studies of fresh water fish, Clarias batradrus (L) exposed to mercuric chloride. IJIB. 2(1): 49-54

 

McCarthy D.H., Stevenson J.P., and Roberts M.S., 1973, Some blood parameters of rainbow trout (Salmo gairdneri Richardson). The Kamloops variety. Journal of Fish Biology, 5, 1–8

https://doi.org/10.1111/j.1095-8649.1973.tb04425.x

 

Monteiro D.A., Rantin F.T., and Kalinin A.L., 2009a, The effects of selenium on oxidative stress biomarkers in the freshwater characid fish matrinxã, Brycon cephalus (Günther, 1869) exposed to organophosphate insecticide Folisuper 600 BR® (methyl parathion). Physiol Comp Biochem C 149: 40-49

 

Nagpal N., 2001, Ambient water quality guidelines for selenium-overview. In: Branch WP, editor: Ministry of Water, Land and Air.

 

Nussey G., Van V., and Du H., 1995, Effect of Copper on the Haematology and Osmoregulation of the Mozambique Tilapia, Oreochromis niloticus (Cichlidade). Comp. Biochem Physiol, 111 (3) 369-380

 

Olanike K.A., 2007, Haematological Profile of Clarias gariepinus (Burchell, 1822) Exposed to Lead. Turkish Journal of Fisheries and Aquatic Sciences 7: 163-169 (2007)

 

Ololade I.A., and Oginni O., 2010, Toxic stress and hematological effects of nickel on African catfish, Clarias garriepinus, fingerlings. Journal of Environmental Chemistry and Ecotoxicology, 22: 14-19

 

Olufayo M.O., 2009, Haematological Characteristics of C. gariepinus juveniles exposed to Derris root powder, African Journal of Food Agricultural and Nutrient Development, 9(3):921-933

https://doi.org/10.4314/ajfand.v9i3.43115

 

Oshode O.A., Bakare A.A., Adeogun A.A, and Sowunmi A.A., 2008, Ecotoxicological Assessment using Clarias garieninus and Microbial Characterization of Leachate from Municipal Solid Landfill, International Journal of Environmental Resource, 2(4): 391-400

 

Pruszynski T., 2003, Effects of feeding on ammonium excretion and growth of the African catfish (Clarius gariepinus) fry, Journal of Animal Science, 48 (3):106 -112

 

Rad F., Kurt G.I., and Bozaoulu A.S., 2003, Effects of spatially localized and dispersed patterns of feed distribution on the growth, size dispersion and feed conversion ratio of the African catfish (Clarias gariepinus), Journal of Animal Science, 28,851-856

 

Rogers J.T., Richards J.G., and Wood C.M., 2003, Ionoregulatory disruption as the acute toxic mechanism for lead in the rainbow trout (Oncorhynchus mykiss), Aquatic Toxicology, 64, 215–234

https://doi.org/10.1016/S0166-445X(03)00053-5

 

Shah S.L., 2006, Haematological parameters of tench, Tinca tinca after short term exposure to lead, Journal of applied toxicology, 26 (3): 223-228

https://doi.org/10.1002/jat.1129

PMid:16389660

 

Singh D., Nath K., Trivedi S.P., and Sharma Y.K. 2008, Impact of copper on haematological profile of freshwater fish, Channa punctatus. Journal of Environmental biology, 29(2), 253

PMid:18831385

 

Vutukuru S.S., 2005, Acute effect of hexavalent chromium on survival, oxygen consumption, haematological parameter and some biochemical profiles of the Indian Major Carp, Labio rohita, International Journal of Environmental Resource and Public Health, 2(2): 456-462

https://doi.org/10.3390/ijerph2005030010

PMid:16819101

 

Witeska M., 2003, The effects of metals (Pb, Cu, Cd, and Zn) on haematological parameters and blood cell morphology of common carp, Rozprawa naukowa nr 72, Wydawnictwo Akademii Podlaskiej Siedlce [In Polish]

PMid:14535641

International Journal of Aquaculture
• Volume 7
View Options
. PDF(237KB)
. FPDF(win)
. HTML
. Online fPDF
Associated material
. Readers' comments
Other articles by authors
. D.O. Odedeyi
. K.E. Odo
Related articles
. Selenium
. Clarias gariepinus
. LC50
. Haematology
Tools
. Email to a friend
. Post a comment