Survey the toxic effect of Abamektin in Artemia franciscana by using Response Surface Methodology

Abamektin is a pesticide which is worldwide application against insect pests in agriculture and livestock activities. But, extensive use of Abamektin and enhanced release into environment can be harmful for aquatic organisms due to their toxic and bioaccumulation properties. This study was carried out as the lethal endpoint bioassay of Abamektin on adult stage of Artemia franciscana (due to their important roles in aquatic ecosystems food chain) in various environmental conditions (variation of pH and salinity) and their interaction by using the response surface methodology. The analysis of central composite design applied for study of three factors including Abamektin concentration (۰.۰۵-۰.۵ μg/l), salinity (۱۰-۲۵۵ g/l) and pH (۴-۱۱) at five levels. The experiment process was conducted in ۲۰ runs in laboratory in ۲۴h. Results showed that the test salinity itself has significant influence on the lethal effect of Abamektin. Dependent on the values obtained by RSM, the model was significant (p<۰.۰۵) with the coefficient of R۲ = ۰.۷۸, Adj R۲ = ۰.۵۹۷, Pred R۲ = ۰.۳۷ and press = ۱۸۳۴.۰۶. Thus the Abamektin has toxic stress on the A. franciscana in high concentration (>۱۳۰ g/l) and low concentration (<۳۰ g/l) of salinities at the concentration rather than ۰.۱۴۵ μg/l of Abamektin. Overall, the Artemia has the capacity to tolerate a wide range of salinities, because of balance between the flows of ions from ambient water with their hemolymph through osmoregulation mechanisms which allow them to survival. It is assumed that the lethal effect of Abamektin in low (<۳۰ g/l) and high (۱۳۰< g/l) concentration of salinities, can be due to alteration in osmoregulate mechanisms in A. franciscana rather than optimum condition.

کلیدواژه ها:

Pesticide ، Bioaccumulation ، Central Composite Design ، Osmoregulation