International Journal of Ecology and Environmental Sciences

International Journal of Ecology and Environmental Sciences


International Journal of Ecology and Environmental Sciences
International Journal of Ecology and Environmental Sciences
2020, Vol. 2, Issue 4
Effects of an organophosphate insecticide, chlorpyrifos on the survival of Macrobrachium rosenbergii at various life stages

Kurishuparambil Varghese Stephy Rose, Aneykutty Joseph

The present study investigated the acute toxicity of an organophosphate insecticide, chlorpyrifos used in the paddy fields of Kuttanad, a part of the Vembanad wetland system which is a Ramsar site of international importance in the state of Kerala, India, to various life stages of Macrobrachium rosenbergii, a commercially important and indigenous prawn of Kuttanad. LC50 values were determined using the observations made on the mortality of prawns exposed to 5 different concentrations between the No Observable Effect Concentration (NOEC) and Lowest Observable Effect Concentration (LOEC) of chlorpyrifos. The LC50 values for 24, 48, 72 and 96 h was determined by probit analysis using SPSS, based on which safe concentrations were calculated using Hart’s formula. The study revealed the 96 h LC50 concentrations as 0.00041, 0.022 and 0.038 ppm and safe concentrations as 0.0001, 0.004 and 0.008 ppm for post-larvae, juvenile and adult, respectively of M. rosenbergii. The results revealed that the application of chlorpyrifos in the paddy fields of Kuttanad poses a threat to the existence of the species in its homeland, as the field application concentration (0.0025 ppm) of chlorpyrifos is higher than the safe concentration determined for post-larvae.
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How to cite this article:
Kurishuparambil Varghese Stephy Rose, Aneykutty Joseph. Effects of an organophosphate insecticide, chlorpyrifos on the survival of Macrobrachium rosenbergii at various life stages. International Journal of Ecology and Environmental Sciences. 2020; 2(4): 67-76.