Toxicity of nitrite to larvae of the salamander Ambystoma texanum

Few data exist concerning nitrite toxicity in non-fish vertebrates. Research designed to determine the 96-hour LC50 for aquatic larvae of the salamander (Ambystoma texanum), and whether increased environmental chloride levels suppress nitrite lethality (as reported for fishes and crayfish), is reported. The 96-hour LC50 in low chloride water equalled 1.09 mg per litre nitrite ion, conservative 95 per cent confidence limits extending from 0.48 to 0.2 mg per litre; almost complete mortality was observed in trials at concentrations as low as 2.5 mg nitrite ion per litre. Larvae exposed to 300 mg chloride per litre and 10 mg nitrite per litre suffered no mortality in 96 hours.