OnLine Journal of Biological Sciences

Toxicity of Endosulfan to the Red Hybrid Tilapia

Dwight E. Robinson and Winroy Williams

DOI : 10.3844/ojbsci.2015.6.9

OnLine Journal of Biological Sciences

Volume 15, Issue 1

Pages 6-9


Exposure of mature red hybrid Tilapia sp. to a range of sub-lethal concentrations of endosulfan for 21 days induced a spectrum of often not clearly distinguishable Behavioural Toxic Symptoms (BTS), ranging from reversible to eventually fatal responses. The No Observed Effect Concentration (NOEC: Below the threshold of BTS) and the Lowest Observed Effect Concentration (LOEC: Above the threshold of low intensity and reversible BTS and below the threshold of any mortality) were <0.005 and <0.0075 mg L?1, respectively. Two other categories of BTS were also distinguishable. Medium Observed Effect Concentration (MOEC: Reversible, medium-intensity BTS in 75% and pronounced, lethal BTS in 25% individuals) and Pronounced Observed Effect Concentration (POEC: Leading to mortality of >25% to 50% of the fish) were 0.01 and 0.02 mg L?1, respectively. The 3-day and 21-day LC50 values were 0.031 and 0.016 mg L?1, respectively.


© 2015 Dwight E. Robinson and Winroy Williams. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.