JOURNAL OF ENVIRONMENTAL ENGINEERING AND TECHNOLOGY VOL. 1, NO. 2, MARCH 2012 23Table 2: Heama<strong>to</strong>logical responses <strong>of</strong> <strong>Clarias</strong> gariepinus in various concentrations <strong>of</strong> solution <strong>of</strong> cypermethrin for 10 days (Mean±SD)Conc. Of cypermethrin0.00 0.05 0.10 0.15 0.20 0.25(mlL -1 )PCV (%) 34.76±3.06 a 30.00±6.25 ab 28.33±4.73 b 25.33±5.13 ab 15.66±10.02 ab 8.67±0.58 cHb (g/dl) 11.57±1.03 a 9.97±2.08 ab 9.47±1.57 b 8.43±1.96 ab 8.43±3.37 ab 3.97±0.25 cLeucocrit (%) 4.18±0.00 ab 3.33±2.31 a 2.00±1.00 ab 1.33±0.58 ab 1.00±0.00 b 1.33±0.587 abWBC (x 10 9 cells) 5.43±2.61 a 5.53±1.79 ab 6.20±0.69 ab 7.03±3.33 ab 11.23±0.06 b 15.23±1.29 aNeutrophils (%) 21.67±2.89 a 22.67±7.51 a 23.33±11.55 c 24.67±7.64 d 25.33±7.64 c 26.00±1.00 fLymphocytes (%) 78.33±20.21 a 71.33±20.13 a 71.67±15.14 a 71.67±18.93 a 71.67±15.28 a 41.33±8.08 abEosinophils (%) 10.00±17.32 a 8.33±14.43 a 5.81±4.00 b 4.67±8.08 b 3.41±5.00 b 3.33±8.62 aMonocytes (%) 4.33±5.77 a 3.33±14.43 a 3.01±0.66 a 2.67±3.06 a 1.67±2.89 a 1.01±0.10 aESR (mm/h) 2.33±0.58 b 2.01±1.53 b 3.97±1.15 b 5.67±2.52 b 7.87±2.08 b 14.67±6.43 aThrombocyte (%) 132.67±31.64 ab 120.00±0.58 ab 110.00±138.92 a 98.33±38.19 b 86.67±12.58 ab 53.33±40.72 bRBC 7.32±1.01a 6.01±1.11b 5.24±1.10c 4.01±1.02 ab 3.66±0.86 d 2.98±0.74MCHC (g/dl) 33.00±0.00 a 32.33±0.58 ab 31.67±0.58 c 30.00±0.00 abc 29.00±0.00 a 22.00±0.58 bcMCH (pg) 32.33±0.58 a 31.67±0.58 a 31.67±0.58 a 31.67±0.58 a 32.00±1.00 a 31.33±0.58 aMCV (fl) 96.67±0.58 a 96.33±0.58 a 95.33±1.15 ab 96.00±1.00 ab 96.33±2.08 a 93.33±2.31 bMean with the same superscript in the column are not significantly different (P
JOURNAL OF ENVIRONMENTAL ENGINEERING AND TECHNOLOGY VOL. 1, NO. 2, MARCH 2012 24IV. DISCUSSIONThe water quality variables in the experimentaltanks were within the range acceptable foroptimum performance <strong>of</strong> fish in culture medium(Boyd, 1998). There was concentrationdependent reduction in the values <strong>of</strong> dissolvedoxygen levels in the exposure tanks, an indicationthat cypermethrin affects the dissolved oxygenconcentration during the experimental procedureresulting in asphyxiation. This result agreed withthe findings <strong>of</strong> Gabriel et al. (2006) in <strong>Clarias</strong>gariepinus exposed <strong>to</strong> proxone in the labora<strong>to</strong>ry.The haema<strong>to</strong>logical parameters in the controlgroup falls within the range <strong>of</strong> normal valuesreported for several cultured catfishes (Erondu etal., 1993: Ogbulie and Okpokwasili, 1999;Akinrotimi, 2008). Exposure <strong>of</strong> C. gariepinus <strong>to</strong>sublethal concentrations <strong>of</strong> cypermethrin caused asignificant decrease in the values <strong>of</strong> eosinophils,Hb, PCV, RBC, leucocrit, lymphocytes,monocytes and thrombocytes <strong>of</strong> the fish. Similarreductions were reported by some athors:Sampath et al. (1993) in Oreochromismossambicus exposed <strong>to</strong> OrganophosphorusOmoregie et al. (1994) in Oreochromis niloticusexposed <strong>to</strong> formalin, Svoboder et al. (2001) inCyprinus carpio exposed <strong>to</strong> diazinon and Gabrielet al. (2007) in C. gariepinus exposed <strong>to</strong> refinedcrude oil products kerosene. The reduction inRBC, Hb and PCV which are related <strong>to</strong> oxygencarrying capacity <strong>of</strong> the blood, may be due <strong>to</strong> theinhibition <strong>of</strong> erythropoiesis hemosynthesis, andincrease in the rate <strong>of</strong> erythrocyte destruction inhaemopoietic organs.Concentration dependent exposure <strong>of</strong> C.gariepinus <strong>to</strong> cypermethrin in this work caused areduction in the lymphocytes, leads <strong>to</strong>lymphopaenia, an indica<strong>to</strong>r <strong>of</strong> unfavourableenvironment, thus corroborating the reports <strong>of</strong>Oluah and Mgbeka (2004) in C. albopunctatusexposed <strong>to</strong> sublethal concentrations <strong>of</strong> actellic25EC. Also, in this work, the reduction observedin leucocrit which is the leucocyte, thrombocytespacked value expressed as a percentage <strong>of</strong> thewhole blood is comparable <strong>to</strong> that <strong>of</strong> Adhikari etal. (2004) in fresh water teleost, Labeo rohitaexposed <strong>to</strong> cypermethrin and cab<strong>of</strong>uran underlabora<strong>to</strong>ry conditions. This is an indication <strong>of</strong>incipient stressful conditions <strong>of</strong> the fish.The reduction in the values <strong>of</strong> eosinophils andmonocytes reported in this study is in agreementwith the findings <strong>of</strong> Benariji and Rajendranath(1990) in <strong>Clarias</strong> batrachus exposed <strong>to</strong>dichlorvos, but contrary <strong>to</strong> that <strong>of</strong> Velisek et al.(2007) in rainbow trout, after exposure <strong>to</strong>deltamethrin the disparity may be due <strong>to</strong> thedegree <strong>of</strong> potency <strong>of</strong> the <strong>to</strong>xicant and its mode <strong>of</strong>actions in different species <strong>of</strong> fish. The ESRvalue <strong>of</strong> fish exposed <strong>to</strong> cypermethrin increasedsignificantly when compared <strong>to</strong> control values.This corroborates the report <strong>of</strong> Svobodova et al.(2003) in Cyprinus Carpio treated withdeltamethrin. The increase ESR value may bedue <strong>to</strong> fragility <strong>of</strong> erythrocytes as a result <strong>of</strong> stressinduces disruptions in the formation and release<strong>of</strong> erythrocytes from haema<strong>to</strong>paetic tissues(Akinrotimi et al., 2010b).Another type <strong>of</strong> haema<strong>to</strong>logical response <strong>to</strong> theeffect <strong>of</strong> cypermethrin was a significantincrement in WBC. This response was equallyobserved in common carp Cyprinus carpio afteracute effect <strong>of</strong> phenitrothion, imidan anddichlorvos (Svobodova, 1991, 1996, 1998). Thismay be due <strong>to</strong> release <strong>of</strong> white blood cells fromspleen in<strong>to</strong> the blood stream <strong>to</strong> combat the<strong>to</strong>xicant.Alteration in the erythrocytes indices <strong>of</strong> C.garipienus, consequent <strong>of</strong> cypermethrinexposure, caused a non significant change withno definite trend, this is in line with theobservation <strong>of</strong> Tsuda et al. (2007) in killifishsubjected <strong>to</strong> organophosphorus insecticide in thelabora<strong>to</strong>ry.V. CONCLUSIONEvaluation <strong>of</strong> haema<strong>to</strong>logical parameters <strong>of</strong>fish exposed <strong>to</strong> <strong>to</strong>xicants in this study, providedvaluable information in the assessment <strong>of</strong> fishhealth and in moni<strong>to</strong>ring stress responses. Theexposure <strong>of</strong> C. gariepinus <strong>to</strong> sublethalconcentrations <strong>of</strong> cypermethrin caused markedvariations in the blood indices <strong>of</strong> the fish anindication that this chemical is highly <strong>to</strong>xic t<strong>of</strong>ish and its use should be controlled so as <strong>to</strong>prevent its entrance in<strong>to</strong> water bodies <strong>to</strong> minimizeaquatic pollution consequent <strong>of</strong> agrochemicals.REFERENCES[1] Adhikari, S., Sarkar B., Chatterjee, A., Mahapatra, C.T.and Ayyappan, S. Effects <strong>of</strong> cypermethrin andcarb<strong>of</strong>uran on certain haema<strong>to</strong>logical parameters andprediction <strong>of</strong> their recovery in a freshwater teleost Labeorohida. Eco<strong>to</strong>xicology and Environmental Safety. 2004.58:220 – 226.[2] Akinrotimi, O.A. Comparative haema<strong>to</strong>logy <strong>of</strong> someculturable clariids raised in freshwater tidal and stagnantearthen ponds. M.Sc Thesis submitted <strong>to</strong> theDepartment <strong>of</strong> Fisheries, Rivers State University <strong>of</strong>24
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