LC50 Determination of ferrous iron (Fe2+) in common carp (Cyprinus carpio)

In current investigation، acute toxicity of ferrous iron was determined based on OECD guideline and Semi-static method. 190 fries of common carp (mean weight: 15±5 gr) were divided in six treatments (10 fries in each treatment) and one control group. There replicates run for each treatment. Qualitative Parameters of water including pH، dissolved oxygen، total hardness، temperature and other parameters were monitored and recorded during test period. Due to constancy of ferrous concentrations in test solutions، pH was maintained at 5. 5±0. 1. Furthermore، to ensure that desirable ferrous concentrations were created and constant during test period، ferrous concentrations were determined by use a spectrophotometer، based on Orthophenontroline method. According to results of acute toxicity test، LC50 values in 24، 48، 72 and 96 hours were calculated by probit analysis method، respectively: 2. 35، 2. 15، 1. 95 and 1. 85 mg/l Fe2+. LOEC and NOEC values were also determined by an analysis of variance، respectively 1. 1 and 1. 5 mg/l Fe2+. MATC value was calculated 1. 5 mg/l Fe2+ as the geometric mean of the LOEC and NOEC.