氨水对三疣梭子蟹幼体的急性毒性影响

开展了氨水对三疣梭子蟹各期幼体的急性毒性实验．结果表明：三疣梭子蟹各期幼体间对氨水的耐毒能力有随时间更迭的现象，半致死浓度LC50值，在24h及48h内，由大到小依次为M、Z3、Z4、Z2和Z1，而72h内则依次为M、Z3、Z2、Z1和Z4．经u检验发现，饥饿组与投喂组间对氨水的耐毒能力无显著差异，饥饿组72h的半致死质量浓度LC。值按幼体发育的先后次序依次为0．486，0．488，1．109，0．273，1．618mg／L，投喂组72h的半致死质量浓度Lc蜘值依次为0．356，0．719，1．592，0．359，3．273mg／L．最后，在分析三疣梭子蟹幼体对氨水的安全浓度、各期幼体间的耐毒特征的基础上，指出可将乙对氨水的安全浓度作为三疣梭子蟹苗种培育的安全浓度，其安全浓度值可取为0．027mg/L．

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.