Alterations in the Serum Electrolytes of the Indian Skipper Frog Euphlyctis cyanophlyctis caused by an Organophosphate Pesticide: Chlorpyrifos

摘要

The aim of the present study is to determine the changes in blood electrolytes (calcium and phosphate) in the Indian skipper frog Euphlyctis cyanophlyctis following short-term and long-term treatments with chlorpyrifos. To determine the effects of short-term exposure, the frogs were exposed to 3.99 mg/L of chlorpyrifos (i.e. 0.8 of 96 h LC50 value) for ninety-six hours. To investigate the effects of long-term exposure, the frogs were exposed to 0.99 mg/L (0.2 of 96 h LC50 value) of chlorpyrifos for 30 days. The frogs were sacrificed after 24, 48, 72 and 96 hours (for short-term experiment) or after 5, 10, 15 and 30 days (long-term experiment). Blood samples were collected and serum calcium and phosphate levels were analyzed. Student’s t test was used to determine the statistical significance difference between the experimental group and its specific-time control group. Exposure of the frog Euphlyctis cyanophlyctis to chlorpyrifos causes a decrease in the serum calcium levels after 48 hours. This decrease continued up to the end of the experiment (96 hours). The serum inorganic phosphate levels decrease progressively 72 hours onwards following the chlorpyrifos exposure. In the long-term experiment, the first perceivable change has been noticed on day ten in the serum calcium as the levels decreased at this interval. The levels continued to fall progressively till the end of the experiment (thirty days). The serum phosphate levels of the chlorpyrifos-treated Euphlyctis cyanophlyctis show a decrease on day ten and fifteen. However, on day thirty, the levels were almost normal. The changes noticed in the blood electrolytes may cause disturbances in the vital physiological functions of the frog, growth and even its ability to survive in nature.