ABSTRACT

The effect of roundup (Glyphosphate herbicide) on the fatt:y acid composition was evaluated in a gravimetric continuous flow - through bioassay employing an autodelivery system at acute and sublethal test for exposure period at lOppm, 20ppm, 30ppm, 40ppm, and 50ppm to Oreochromis niot/cus fingerlings. The result showed the 96hLc50as 39.8lppm. The threshold value was 12.30ppm. The fatty acid composition was also evaluated at sublethal concentration (1/3 96hLc50was 13.27ppm) at 1,3,5,7 days intervals. The statistical analysis of the data showed there was a significant difference among the various fatly acid recorded at P<O.05 with dedecanoic acid recording the highest value (7.71%) and linoleic acid recording the least value (2.21%). During acute exposure period the fish gasped for air with their snout above the water surface indicating respiratory distress. Other behaviour responded were loss of balance, erratic swimming, and finally death. It is evident from the result that Oreochrom/s niotIcus cannot survive beyond the safe level (12.30ppm) indicated in this research and also deduced that the fatty acid composition is also elevated over and above the control indicating mass mobilization of fat during stressful condition and starvation. It should be noted that to avoid toxicological effects, this herbicide should be applied carefully using lowest possible dose.