Acute Toxicity of Phenol,Pentachlorophenol and Sodium Pentachlorophenate to a Freshwater Ostracod Cypris subglobosa (Sowerby)

The toxicity of phenol, pentachlorophenol and Na-pentachlorophenate to Cypris subglobosa is determined in the batch experiment for 96. h. In the sequence mentioned, the LC_50,96h of the three substances are 71.8, 6.56 and 4.41 mg/l, respectively. In the range of 6 … 95 h the mean survival time shows a negative regression to the toxicant concentration, which, however, is not significant statistically for Na-pentachlorophenate. In agreement with this, the LC₅₀ for 12, 24, 48, 72 and 96 h of exposure shows a significant decrease. Due to the comparatively high LC_50,96h for pentachlorophenol and Na-pentachlorophenate for C. subglobosa about in comparison with fish, the species is little suited to the toxicological investigation of wastewater.