Abstract: Acute toxicity of low pH to Marsupenaeus japonicus was studied by hydrostatic experiment. We selected Marsupenaeus japonicus with an average length of (48.87±4.81) mm as experimental subjects, and set pH gradient as Marsupenaeus japonicus3.8, 4.1, 4.4, 4.7, 5.0 and pH of control group as 8.0±0.1 to investigate the mortality of Marsupenaeus japonicus under low pH stress and analyze the semi-lethal concentration (LC50) and semi-lethal time (LT50) of Marsupenaeus japonicus under pH stress. The results showed that: the mortality of Marsupenaeus japonicus increased with time under the same pH. There was a negative correlation between the mortality of Marsupenaeus japonicus and the pH in water (R<0, P<0.01) at the same stress time. The LC50 of Marsupenaeus japonicus under stress of 48 h, 72 h, 96 h with pH was 7.907×10-5, 5.14×10-5 and 3.673×10-5 mol/L, and safe concentration (SC) was 3.673×10-6 mol/L, corresponding pH was 4.102, 4.289, 4.435 and 5.435 respectively. The LT50 of Marsupenaeus japonicus under water pH=4.1, 4.4, 4.7 was 58.821, 93.771, 139.549 h respectively. This study provided a basis for studying the breeding of Marsupenaeus japonicus, the tolerance to low pH and the selection of low pH resistant strains.

Key words: pH, acute toxicity, Marsupenaeus japonicus, larva

摘要： 采用静水试验方法，研究低pH对日本囊对虾的急性毒性。试验日本囊对虾平均体长(48.87±4.81 ) mm，设定pH梯度为3.8、4.1、4.4、4.7、5.0，对照组pH为8.0±0.1，统计日本囊对虾在低pH胁迫下的死亡率，分析pH对日本囊对虾的半致死摩尔浓度(LC50)和半致死时间(LT50)。结果显示：在相同pH下，日本囊对虾的死亡率随时间延长而增加；在相同的胁迫时间内，日本囊对虾死亡情况与水体pH呈负相关(R<0，P<0.01)；pH对日本囊对虾胁迫48 h、72 h、96 h的半致死摩尔浓度(LC50)分别为：7.907×10-5、5.140×10-5和3.673×10-5 mol/L，安全摩尔浓度(SC)为3.673×10-6 mol/L，对应的pH分别为4.102、4.289、4.435、5.435；水体pH4.1、pH4.4、pH4.7胁迫日本囊对虾的半致死时间(LT50)分别为58.821、93.771和139.549 h。本研究可为研究日本囊对虾的养殖、对低pH的耐受性及耐低pH品系选育提供依据。

关键词: pH, 急性毒性, 日本囊对虾, 幼虾