Toxicity of phenol on Macrobrachium rosenbergii (de Man) eggs, larvae, and post-larvae

The toxicity of phenol solutions to eggs, larvae and post-larvae of the Malaysian freshwater prawn (Macrobrachium rosenbergii) was assessed in continuous flow experiments. Phenol was measured by UV absorption at 194 nm in freshwater and 210 nm in brackish water. Acute 48-h LC50 values for larval and post-larval stages were 11.83-19.48 and 22.25-29.04 mg phenol per litre, respectively, the higher values applying to the post-larval stages. The 12-d EC50 for hatching rate was 0.961 mg phenol per litre. Safety levels of 0.088, 0.118 and 0.196 mg phenol per litre were recommended for hatching, larval and post-larval stages to protect this organism.