Acute toxicity of phasetreat 4633 (demulsifier) against the cichlid, Tilapia guineensis (Gunther, 1862)

Abstract

The acute toxicity of phasetreat 4633 (Demulsifier) against the cichlid, Tilapia guineensis (fish) was determined using the Organisation of Economic Development and Cooperation (OECD) #203 protocol. Tilapia guineensis were exposed to concentrations of 6.25, 12.5, 25, 50 and 100 mg/l for 96 h. The 96h LC50 (19.32 ± 4.0 mg/l) obtained using the Finney Probit analysis revealed that the test chemical was slightly toxic to the test organisms based on international protocols. There was statistical significance between mortality in the Phasetreat experiment and the control treatments at levels of p < 0.05. Varying behavioural patterns were observed in the fish, which included erratic swimming, loss of reflexes, total loss of equilibrium, paleness of skin and gasping for air. These are possible signs of water quality deterioration and ecological effects on these economically viable species. The likely result of this effect could possibly lead to a high distortion and imbalance of the aquatic ecosystem if such hazardous chemicals are released into aquatic environment. Key words: acute toxicity; demulsifier; cichlid; Tilapia guineensis .