Abstract

The present research was performed to determine and compare acute toxicity of diazinon and deltamethrin to spirlin larvae and fingerling. Diazinon and deltamethrin are common useful agricultural pesticides. LC₅₀ of 24, 48, 72 and 96 h was attained by probit analysis software SPSS Version 16. Fish samples (21 fish in each test group) were exposed to different concentrations of diazinon and deltamethrin (diazinon: for fingerling between 1 to 20 ppm and larvae 0.25 to 2 ppm; deltamethrin: for fingerling between 0.01 to 0.2 ppm and larvae 0.0025 to 0.02 ppm) for 96 h and mortality were recorded. The LC₅₀ 96 h of diazinon for fingerlings and larvae were 7.88 and 0.69, respectively. The LC₅₀ 96 h of deltamethrin for fingerlings and larvae were 0.27 and 0.006 ppm, respectively. According to the results, larvae are more sensitive than fingerlings. In the present study, LC₅₀ values indicated that deltamethrin is more toxic than diazinon to this species.

Key words: Diazinon, deltamethrin, lethal toxicity, Alburnoides bipunctatus.