TOXICITY OF ATRAZINE (HERBICIDE) TO JUVENILES OF THE AFRICAN CATFISH, CLARIAS GARIEPINUS (BÜRCHELL, 1822)

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dc.contributor.authorBAYERO, Umar
dc.date.accessioned2018-12-04T13:33:39Z
dc.date.available2018-12-04T13:33:39Z
dc.date.issued2017-02
dc.descriptionA THESIS SUBMITTED TO THE SCHOOL OF POSTGRADUATE STUDIES, AHMADU BELLO UNIVERSITY, ZARIA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE AWARD OF MASTER DEGREE IN BIOLOGY DEPARTMENT OF BIOLOGY FACULTY OF LIFE SCIENCES AHMADU BELLO UNIVERSITY, ZARIA, NIGERIAen_US
dc.description.abstractIn the present study, juveniles of Clarias gariepinus were exposed to the herbicide atrazine in order to determine the herbicide‟s toxicity to the species at both acute and sub-lethal exposures.Fish were exposed to acute concentrations of 9, 10, 11, 12 and 13mg/L of atrazine, as well as sub-lethal doses of 0.59, 1.19 and 2.38mg/L of atrazine. Both experiments had a control that served as a reference point. Effects of the herbicide were measured using behavioural, haematological, biochemical, histopathological as well as growth indices (as suggested by previous authors). Results of the acute toxicity test showed that atrazine was toxic to the species in a dose-dependent manner. The LC50 value of atrazine established for the species was 11.89mg/L. Most importantly, atrazine induced hyperactivity at acute levels of exposure. Significant (p<0.05) haematological changes observed at both acute and sub-lethal exposures included anaemia, leukocytosis, proteinaemia, haemoglobinaemia, neutrophilia as well as lymphocytosis. Acute and sub-lethal concentrations of atrazine also induced an increase in the generation of reactive oxygen species. Histopathological changes observed in the gills included attenuation and clubbing at the tips of the primary lamellae, gradual degeneration of the primary lamellae, total dislocation of the primary lamellae from its position as well as mild congestion in the cartilage. Changes in the liver of exposed fish included perivascular cuffing around the central vein, mild congestion of the sinusoids, pyknosis of the nuclei, mild necrotic damage, congestion of the central vein as well as mild coagulative necrosis. Atrazine also had effect on the growth parameters (weight gain, percentage live weight gain and specific growth rate) as well as nutrient utilization parameters (feed conversion efficicency, feeed conversion ratio, gross feed conversion efficiency and nitrogen metabolism) although some of these effects were not statistically significant (p>0.05). The study revealed that atrazine was moderately toxic to C. gariepinus juveniles and affected the behaviour, haematology, biochemistry, histology as well as growth of the fish. Hence, use of the herbicide should be with caution especially near water bodies.en_US
dc.identifier.urihttp://hdl.handle.net/123456789/11044
dc.language.isoenen_US
dc.subjectTOXICITY,en_US
dc.subjectATRAZINE (HERBICIDE),en_US
dc.subjectJUVENILES,en_US
dc.subjectAFRICAN CATFISH,en_US
dc.subject, CLARIAS GARIEPINUS,en_US
dc.subject(BÜRCHELL, 1822)en_US
dc.titleTOXICITY OF ATRAZINE (HERBICIDE) TO JUVENILES OF THE AFRICAN CATFISH, CLARIAS GARIEPINUS (BÜRCHELL, 1822)en_US
dc.typeThesisen_US
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