Morphometric indices and Oxidative Stress Biomarkers of African Catfish Clarias gariepinus juveniles Exposed to Agricultural Fungicide Mancozeb

Abstract

Ursula Odo, Iyikite Ebuka, F Chijioke and GE Odo3

The present study investigated the morphometric indices and oxidative stress biomarkers of African Catfish Clarias gariepinus juveniles exposed to agricultural fungicide mancozeb. A total of 150 Clarias gariepinus with standard length and weight that ranged from 9.8 cm to 17.5 cm and 11 g to 55 g respectively were used for the experiment. The 96hours LC50 value of Mancozeb on Claria s gariepinus juveniles was estimated to be 410.90mg/L. The sub-lethal four treatments were exposed to 0.00. 20.55, 41.09 and 82.18 mg/L (A-D) Mancozeb fungicide. Each group were replicated three times consisting of 10 fish per replica summing up to 30 fish. The physico-chemical parameters of water observed for five weeks showed changes and fluctuations on temperature range from 28°C to 32°C, pH levels ranged from 7.3 to12.3, Alkalinity range 0.88 to 4.10mg/L, CO2 values ranged from 3-12.5mg/L. While dissolved oxygen from 6.6 to 7.8mg/L. Behavioral changes observed after 24-96hours of fish exposure to different concentrations of Mancozeb revealed loss of equilibrium status and respiratory difficulties. Morphometric indices such as condition factor and hepatosomatic indices were not significantly different when compared to the control group. The oxidative stress parameters were studied in the kidney, liver and gill tissues and sampling was done on days 1, 7, 14, 21 and 28 (after 7days recovery). The result of the present study on antioxidant parameters revealed that changes on oxidative stress parameters of LPO, CAT, SOD, GPx, GR and MDA were all concentration and duration dependent. Oxidative stress revealed that Lipid peroxidation significantly increased (P�? 0.05) on day 21 and 28 compared to control, CAT was not significantly different when compared to control group. SOD significantly decreased on day 7, 14, 21 compared to control, GPx significantly decreased on day 1 and 21 compared to control, GR significantly increased on day 7 and 21 compared to control, MDA significantly increased on day 1, 28 and 7 compared to control. Mancozeb is moderately to highly toxic to C. gariepinus juveniles. There was no significant difference in the morphometric indices compared to control groups.

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