Acute Toxicity of Ammonia on Portunus trituberculatus Larvas

The paper studied the acute toxicity of ammonia on the different period larvas of Portunus trituberculatus.The result showed that the enduring capacity of Portunus trituberculatus larvas to ammonia changed with time,ie.the value of half lethal concentrations(LC_(50)) in 24 h and 48 h from low to high was M(megalopa),Z_3,Z_4,Z_2 and Z_1,while in 72 h it was M,Z_3,Z_2,Z_1 and Z_4 in turn.U checking showed that the enduring capacity of Portunus trituberculatus larvas to ammonia was no significant difference between the starvation group and feeding one,the LC_(50) in 72 h in starvation group was 0.486,0.488,1.109,0.273,(1.618 mg/L) from Z_1 to M in turn,and in the feeding group 0.356,0.719,1.592,0.359,3.273 mg/L from Z_1 to M in turn.Finally,based on the analysis of the safe concentration and the endurance to ammonia,the result can be obtained that the safe concentration of Z_4 to ammonia may be considered as the safe concentration during whole larvas breeding of Portunus trituberculatus,ie.0.027mg/L.