Haematotoxicity of Cypermethrin to African Catfish Clarias ...

JOURNAL OF ENVIRONMENTAL ENGINEERING AND TECHNOLOGY VOL. 1, NO. 2, MARCH 2012 21al., 2006), Monocrotophous (Yaji and Auta,2007), Kerosene (Gabriel et al., 2007). Thesestudies showed that various degrees ofhaematological changes could be produced byexposure of C. gariepinus to different levels oftoxicants under laboratory conditions.Despite a number of studies on the effects oftoxicants on haematology of C. gariepinus littleis known on the haematological changes that C.gariepinus may suffer under exposure tocypermethrin, a pesticide commonly applied inagriculture operations. The present study wascarried out to assess the effect of exposure of C.gariepinus to cypermethrin on its haematologicalparameters under laboratory conditions.II. MATERIALS AND METHODSA total of 18 Clarias gariepinus (mean bodyweight 276.44g ±8190SD and mean total length29.47cm±1.88SD) were obtained from a privatefarm of Abuloma Town in Port Harcourt LocalGovernment Area of Rivers State in Nigeria.They were then transported in plastic aquaria tothe fisheries research laboratory of the RiversState University of Science and Technology, PortHarcourt, Nigeria. The fish were acclimated tolaboratory condition for a period of one week.During the exposure period, the fish were fed oncommercial diet (35%CP) once a day at 3% oftheir body weight.After the period of acclimation, the fish wererandomly distributed into eighteen glass aquaria(56 x 28 x 28cm) with 30 litres of water at threefish per aquarium. Each of the aquaria containedeach of the following concentrations ofcypermethrin: 0.05, 0.10, 0.15, 0.20 and 0.25ml/l. The control group of fish were kept inaquaria devoid of toxicant (0.00mlL -1 ) each ofthese treatments had three replicates. During theexposure period which lasted for 10days, somewater quality parameters namely pH,conductivity, dissolved oxygen, alkalinity andhardness were measured thrice using the methodsdescribed by APHA (1985). Fresh preparation ofthe test solution were introduced into theexperimental media on daily basis.At the end of the experiment, blood wascollected from the fish by cardiac puncture usinga 21 – gauge hypodermic needle and syringe.The following haematological parametershaemoglobin (Hb), Packed Cell Volume (PCV),Red Blood Cell (RBC) and ErythrocyteSedimentation Rate (ESR), were determinedusing the methods described by Blaxhall andDaisley (1973). Differential counts (neutrophils,lymphocytes, eosinophils, monocytes) andleucorit were evaluated according to McLeay andGordon (1977). Red blood indices such as meancorpuscular haemoglobin concentration (MCHC),mean corpuscular haemoglobin (MCH), andMean Corpuscular Volume (MCV) werecalculated using the formula of Seiverd (1983).Data obtained from the study were analyzed bya one-way analysis of variance (ANOVA) test at0.05% probability level and differences amongmeans were indicated using Tukey test (Zar,1984).III. RESULTSThe water quality parameters in the varioustreatment levels (Table 1) showed that there wereno significant differences between the treatmentand the control. The haematological changesproduced by the effects of exposure of C.gariepinus to different levels of the pesticideunder daily renewal condition showed asignificant (p