Pensee Journal
Vol 76, No. 5;May 2014
Effect of an organophosphate insecticide, chlorpyrifos on mortality and haematology of freshwater butter catfish Ompok bimaculatus (Bloch, 1794) A. Mishra*, N. Mishra, A. Rawat, S. Verma Department of Applied Animal Sciences, Babasaheb Bhimaroa Ambedkar University, Lucknow, U.P., India *Correspondence to: (A. Mishra) Department of Applied Animal Sciences, Babasaheb Bhimrao Ambedkar University, Raebareli Road, Lucknow - 226025, India., Phone number: 09450710387, E-mail address:
[email protected] Abstract The aim of the present study was to evaluate the toxicity effect of an organophosphate insecticide, chlorpyrifos (CPF) on survival and haematological parameters of the fresh water fish Ompok bimaculatus. For this acute toxicity test was done with different concentration of CPF for 24 h exposure duration. In this the detected LC50 value of CPF was 0.963µl/L. The erythrocyte (RBC) count and haemoglobin (Hb) content showed significant decrease (p < 0.05) as compared to the control group whereas the white blood cell (WBC) count was increased significantly (p < 0.05).The morphological changes in the blood cells were also reported with effect of CPF. The CPF leads to decrease in RBC and Hb showed the decrease oxygen level in blood that leads to hypoxia condition and death of animal whereas increase count of WBC represents stress condition and its important role in immune system. Keywords: Toxicity, Ompok bimaculatus, Haemoglobin, Erythrocyte count, White Blood Cell count 1.Introduction The most widely used class of insecticides in the world is the organophosphates (OPs) which are biologically active chemicals of great value to agriculture and domestic purposes (Khogali et al., 2005; Ali et al., 2009). CPF {O,O–diethyl–O (3, 5, 6-trichlor-2-pyridyl) phosphorothioate; CPF} is a broadspectrum synthetic organophosphate insecticide and acaricide, acting as a cholinesterase inhibitor (Bailey et al., 1997). The primary concern about the CPF is its aquatic toxicity which includes neurological, anatomical, behavioural and possibly reproductive effects (Devi and Mishra, 2013). Different water pollutants and toxicants such as organophosphate cause physio-pathological changes, nutritional status, toxicological effects and environmental stress. The haematological parameters of fishes are important tool for assessment of these stress conditions (Xiaoyun et al., 2009). Qualitative and quantitative variations in blood parameters including the red blood cell (RBC) and white blood cell (WBC) numbers, the amount of haemoglobin (Hb) are the important parameters in diagnosing the structural and functional status of fish exposed to toxicants (Mcleay and Gordon, 1977; Adhikari and Sarkar, 2004) and oxygen carrying capacity of blood stream (Shah and Altindag, 2004). An indigenous freshwater butter catfish, Ompok bimaculatus (Bloch, 1794) belongs to the Siluridae family of the order Siluriformes which is widely distributed along the plains and submountain regions covering South East-Asia. The decrement in population are likely to be loss of habitat due to riverine siltation, disease, pollution, poisoning, destructive fishing in breeding season, high exploitation (Parameswaran et al., 1970). There is no published account on the haematological studies with respect to the acute toxicity of CPF in O. bimaculatus. So the present piece of work has been undertaken for the first time as a primary effort to analyse the lethal effects of CPF on adult and blood parameter of the freshwater fish O. bimaculatus. 2. Materials and Methods 2.1. Chemicals The toxicity studies were conducted using CPF (CPF) which was procured from the local market of Lucknow, Uttar Pradesh, India, under the trade name Hilban (20% EC CPF), supplied by Hindustan
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Pensee Journal
Vol 76, No. 5;May 2014
insecticide limited. Hayem’s diluting fluid (Molychem), Turk’s diluting fluid (Molychem) and other used chemicals were of analytical grade and purchased locally from scientific suppliers. 2.2. Animal collection and their acclimatization The freshwater fish O. bimaculatus, of relatively same size (16±2 cm) and weight (29±4 gm) were collected from Gomati River, Lucknow. The live fishes were brought to the laboratory and were acclimatized under normal photoperiod and temperature for 7 days in aquaria. During this period, fishes were fed regularly with commercial fish food pellets but feeding was stopped two days prior to exposure to the test medium for acute toxicity test. 2.3. Experimental set-up Acclimatized fish were divided in two groups, control and experimental. Experimental fish were exposed to different concentrations of Hilban (0.01, 0.05, 0.1, 0.5, 1, 5, 10, 15, 20 and 25 µl/L) for 24 hr. The aquarium receiving only water served as control. In each set, including control, ten fish were taken. The experiment was set in triplicate. No food was supplied during the experiment duration. 2.3.1. Effect of CPF on mortality At the end of experimental duration (24 hr) mortality was recorded for each concentration of CPF and control set. 2.3.2. Effect of CPF on haematological parameters On completion of experiment (24 hr), the blood was collected from caudal vein of fish via heparinised needle to study the CPF concentration effect from each group. The RBC and WBC counts were determined by improved Neubaurer haemocytometer (Shah and Atindag, 2004,2005). In brief, for RBC counting, blood was diluted with Hayem’s solution (1:200) (Shah et al., 2004), and for WBC counting blood was diluted with Turk’s diluting fluid (1:20) (Wintrobe, 1967) and placed in haemocytometer for cell counting. The haemoglobin content determined by Sahlin-Hellige method. In brief, N/10 HCl solution was filled in the graduating tube. Fresh blood was sucked by micropipette, was then added to N/10 HCl solution in the tube. The solution was thoroughly stirred with the help of a glass rod and the stand for 5-10 minutes. Afterwards distilled water was added in a drop wise manner for diluting the solution. This was continued till the colour of the solution matched with that of standard sealed tube. Then the value was recorded and expressed in g/100 ml. 2.3.3. Effect of CPF on morphology of blood cells Thin blood films were prepared using Geimsa stain and observed of both experimental and control groups to see the concentration effect of CPF on blood cell morphology. 2.4. Statistical analysis LC50 value with 95% confidence limits were estimated by Probit analysis by SPSS software (IBM SPSS Statistic 20). Data are expresses as the mean ± S.E. Statistical analysis was done by one way analysis of variance (ANOVA) followed by Newman Keul’s test to compare effects between different concentrations. The level of significance was seen at P
