Acta Vet. Brno 2006, 75: 107-113

Nitrite Toxicity to Danio Rerio: Effects of Fish Age and Chloride Concentrations

E. Voslářová, V. Pištěková, Z. Svobodová

Department of Public Veterinary Medicine and Toxicology, University of Veterinary and Pharmaceutical Sciences Brno, Czech Republic

Received October 17, 2005
Accepted March 16, 2006

The aim of the present study was to compare the acute nitrite toxicity for Danio rerio at the age of 20-25 days (larval stage) and 2-3 months (juvenile stage) at various chloride concentrations. The semistatic method according to OECD 203 was used in the tests. The 96hLC50 NO2- value was 386.00 ± 29.75 mg l-1 (D. rerio aged 20-25 days), and 242.41 ± 13.67 mg l-1 (D. rerio aged 2-3 months), respectively, at 19 mg Cl- l-1 in diluting water. We observed an increase in 96hLC50 NO2- in D. rerio of both developmental stages following an increase in Cl- concentration in diluting water. A comparison between the 96hLC50 NO2- determined for D. rerio aged 20-25 days and those aged 2-3 months at different chloride concentrations in diluting water (19; 50; 100 mg l-1) showed a highly significant increase (p < 0.01) in the 96hLC50 NO2- for the younger fish at all chloride concentrations. An exponential relationship between 96hLC50 NO2- values and chloride concentrations in diluting water (I = 0.849) was demonstrated in D. rerio aged 20-25 days while a logarithmical relationship (I = 0.856) was observed in D. rerio aged 2-3 months.