艾比湖卤虫滞育诱导的临界光周期和感知光照度的研究

Critical Photoperiod and Sensitive Light Intensity of Diapause Induction in Parthenogenetic Artemia(Crustacea:Anostraca)from Aibi Lake,China

卤虫具有滞育模式（卵生）和非滞育模式（卵胎生）两种繁殖模式,而光周期可能是影响其繁殖模式的重要的环境因子,因此明确其临界光周期和感知光照度对于有效地调控卤虫滞育、繁殖等将具有重要实践意义。本研究在实验室条件下研究了艾比湖卤虫的临界光周期和感知光照度,结果表明,在常规养殖盐度（80）和温度（25℃）条件下,艾比湖卤虫的光反应曲线与典型的长日照反应型滞育昆虫类似,在非极端光周期下,艾比湖卤虫的临界光暗时长为（8.38±0.37）h,相应的临界日长为15.62h;在极端光周期下,24h光暗时长,滞育率为（32.42±6.70）%,极显著低于邻近长光暗时长滞育率（P〈0.01）;0h光暗时长,滞育率为（19.01±5.98）%,较邻近短光暗时长滞育率略高,但差异不显著（P〉0.05）。感知光照度试验表明,艾比湖卤虫感知光照度可能处于10-50lx。本研究为卤虫的滞育诱导和繁殖模式的光控化养殖提供了重要的科学基础。

The embryonic development of Artemia follows two modes, oviparity with production of encysted diapause embryos （cysts, diapause mode） and ovoviviparity with release of live nauplii （nondiapause mode）. Recent results show that photoperiods probably is the major token stimuli in Artemia diapause induction. It is meaningful to get critical photoperiod and sensitive light intensity in Artemia culture. With this purpose, critical photoperiod and sensitive light intensity were assayed using a parthenogenetic Artemia from Aibi Lake （Xinjiang, China） a laboratory at a salinity of 80 at 25 ℃. The photoperiodic response curves of this population showed similarity with typical long-day species of insect with a critical dark length of （8.38±0.37） h （base on the data except the constant light and constant dark group）. About the two extreme situations, the diapause incidence was （32.42± 6.70）%, significantly lower than other nearby long darkness photoperiods（P〈0.01） under constant darkness, and the diapause incidence （19.01±5. 98）% was slightly higher at constant light than other nearby short darkness photoperiods, without significant difference （P 〉 0. 05）. Sensitive light intensity experiment under long-photoperiods （18L ： 6D） showed that the sensitive light intensity of this population perhaps lied between 10 lx and 50 lx. All these findings are important for understanding of Artemia diapause induction, with practical applications for management of Artemia reproduction under control.