摘要 在(25±1)℃恒温条件下，研究了圆形盘肠溞Chydorus sphaerius在不同盐度下的急性和慢性试验。急性盐度试验设置盐度为1、2、3、4、5、6、7，观察不同时刻溞体的死亡情况，计算24 h半致死浓度(24 h LC50)，慢性试验设置盐度为0.5、1.0、1.5、2.0、2.5，进行圆形盘肠溞的寿命、发育、繁殖和种群增长试验，每个试验的每个盐度组均设5个重复。结果表明：急性盐度试验中，圆形盘肠溞的24 h LC50 为2.64 mg/L；慢性盐度试验中，低盐度0.5组圆形盘肠溞的内禀增长率和周限增长率均高于对照组，且产前发育期随盐度的增加有不同程度的缩短，这显示了盐度对其繁殖的积极作用，但盐度为1.5及以上的试验组，圆形盘肠溞的内禀增长率、世代周期、净生殖率和周限增长率均与对照组有显著性差异(P<0.05)。研究表明，圆形盘肠溞对盐度变化较为敏感，其能否作为海产苗种的一种饵料，需要盐度驯化的进一步研究。
Abstract: The acute (a salinity of 1, 2, 3, 4, 5, 6 and 7) and chronic (a salinity of 0.5,1.0, 1.5, 2.0, and 2.5) test of salinity to water fleas Chydorus sphaerius were investigated with pentoplication at water temperature of (25±1)℃. In the acute salinity test, the 24 h median lethal concentration (LC50) was found to be 2.64 mg/L, and in the chronic salinity test, the water fleas had higher intrinsic rate and finite rate of increase at low salinity of 0.5 than those in control group, with shorter pre-reproduction developmental stage with the increase in salinity, showing positive effect of salinity on reproduction. At a salinity of 1.5 or over, there were significant differences in the intrinsic rate of increase, mean generation time, and net productive rate in the test groups from the control group (P<0.05). The findings indicated that the water fleas was sensitive to change in salinity, and whether it can become a natural food or not in aquaculture needs to be further study of salinity domestication.
李双宇, 揣洁, 崔延超, 刘青. 盐度对圆形盘肠溞存活、生长和繁殖的影响[J]. 大连海洋大学学报, 2015, 30(1): 36-40.
LI Shuang-yu, CHUAI Jie, CUI Yan-chao, LIU Qing. Influence of salinity on the mortality, growth and reproduction of water fleas Chydorus sphaerius. Journal of Dalian Ocean University, 2015, 30(1): 36-40.
2015, Vol. 30 
