University of Khartoum

Studies on Some Effects of the Pesticide Endosulfanon the Nile Tilapia Oreochromis niloticus

Studies on Some Effects of the Pesticide Endosulfanon the Nile Tilapia Oreochromis niloticus

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Title: Studies on Some Effects of the Pesticide Endosulfanon the Nile Tilapia Oreochromis niloticus
Author: Alim, Dina Ibrahim Mohamed Ibrahim
Abstract: The Nile Bulti Oreochromis niloticus which is one of top important economic species in the Nile system was used in investigating the toxicity of, the organochlorine insecticide, Endosulfan to fish. The selected species was exposed to a technical grade of Endosulfan comprising 7:3 alfa to Beta isomers. Exposure was under semi static conditions. Using concentrations of 10, 20, 30, 40 and 50 ppb. The calculated 96 hours half lethal concentrations (LC50) for O. niloticus were 10.7ppb, 26.9ppb, 20 ppb and 31.3ppb for the Age-groups I, II, III and IV respectively. The calculated half lethal Time (LT50) ranged between 3,981 and 1.73 hours for the four Age-Groups being exposed to the different concentrations. Haematological parameters of O. niloticus exposed to the pollutant Endosulfan was found to be affected. There was a significant decrease in Packed Cell Volume (PCV) ranging from 24.7% to 12%, Haemoglobin Content (Hb) ranging from 5.58 to 3.8 g/dl and in Total erythrocyte count ranging from to . A nonsignificant drop in leucocytes counts ranging from to . Haemoglobin indices showed a significant increase in Mean Corpuscular Haemoglobin (MCH) ranging from 41.1 to 53.9 pg, in Mean Corpuscular Haemoglobin Content (MCHC) ranging from 27.98 to 21.7% Mean Corpuscular Volume (MCV) showed a nonsignificant increase throughout the exposure time ranging between 183.1 to 196.8 f1. The differential count showed a nonsignificant decrease in mean thrombocyte % ranging between 87.2 to 84.6%. Mean Monocyte % remained unchanged throughout the experimental period giving a mean of 0.17%. There was a significant decrease in mean Granulocyte % ranging from 12.4% to 6.1%. On the other hand mean Lymphocyte % gave a significant increase in treated O. niloticus, from the control, ranging between 2.8% to 5.9%. The histopathology of Endosulfan in gills, liver, kidney, intestine and stomach was investigated. The gills showed a haemorrhage, telangectiasis (appearance of eosinophils) and haematoxphilic bodies. The liver showed blood congestion, steatosis (Lipid infiltration) followed by focal necrosis, pyknosis, lymphocytic infiltration ending up with general necrosis of the liver. Lipid vaculation and moderate necrosis were the first Histopathological changes observed in the kidney. Shrinkage of glomeruli, hyperplasia of epithelial cells, pyknosis, reduction of haemapoietic tissues in between tubules and moderate haemorrage are also lesions observed in the kidney. The intestine showed shortening of intestinal villi and lymphocytic infiltration, followed by pyknosis and rupture of tips of villi. The stomach showed desquamation of epithelial cells, shortening of villi and pyknosis. Residues in the whole body of O. niloticus exposed to a sublethal dose (20ppb of 50% EC of Endosulfan) at different exposure times were studied. O. niloticus showed a high capacity of absorbing Endosulfan to a certain maximum limit beyond which there was an elimination of the pesticide . A bioaccumulation factor (BAF) of Endosulfan reached a maximum of 3,564 folds after 48 hours of exposure. This was followed by a drop in accumulation reaching undetectable levels at day 11, 1,140 folds at day 13 and 860 folds at day 15. Results indicated that Endosulfan moderately bioaccumulate in the body of O. niloticus. The main and specific objectives targeted in this study have been fulfilled during the execution of this piece of investigation. It is hoped that the findings meet the satisfaction of the practitioners in this and similar programmes
URI: http://khartoumspace.uofk.edu/handle/123456789/13647
Date: 2015-06-17


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