Cnidarians, being regarded as ‘basal' metazoan animals, are considered to have relatively high plasticity in terms of sex reversal. In this study we used an experimental approach to demonstrate sexual diff erenti...Cnidarians, being regarded as ‘basal' metazoan animals, are considered to have relatively high plasticity in terms of sex reversal. In this study we used an experimental approach to demonstrate sexual diff erentiation and plasticity in benthic polyps and pelagic medusae of A urelia sp.1 maintained at dif ferent temperatures. Results indicated that in A urelia sp.1, sex diff erentiation has been determined at the polyp stage and that all medusae originating from a given polyp are, phenotypically, of the same sex. In addition, the sex of polyps budding from the same clone(either male or female) at dif ferent temperatures appears to be the same as that of the parent. The sex of medusae that had originated from a known-sex polyp was observed to remain the same as that of the parent, irrespective of differences in strobilation or rearing temperatures. These results indicate that the mechanism of sex determination of Aurelia sp.1. is not influenced by prevailing temperature regimes. A comparison of variability in terms of sexual plasticity of A urelia sp.1 with that of Hydrozoa and Anthozoa suggests that species characterized by a free-swimming medusa life stage have a high dispersal potential, which probably results in a lower rate of sex reversal.展开更多
文摘为研究海月水母有性繁殖的关键过程,采用实验生态学及显微观察的方法研究了光周期、食物条件、机械损伤对其排精诱导的效果,并对其受精及胚胎发育的详细过程进行了研究。结果发现,长光照(14 L∶10 D)、饥饿、机械损伤等因素能有效诱导性成熟的海月水母排精;海月水母体内受精过程:雌性海月水母伞缘触手将雄性排出的精子细丝收集到伞缘的食物囊处,通过口腕进入口腕基沟,先后经胃口腕沟、胃循环沟等水管系统到达卵巢,精子与成熟卵子结合完成受精;海月水母受精卵为球形,卵径150μm左右,胚胎发育过程包括卵裂期、囊胚形成期、囊胚期、原肠胚形成期、原肠胚期及浮浪幼虫期6个时期。受精卵在(22±1)℃的水温下,经29 h 20 min发育为浮浪幼虫,经过73 h 20 min发育为四触手螅状体。研究为揭示海月水母的暴发机制提供了参考资料。
基金Supported by the Key Research Project of Hainan Province(No.ZDKJ2016011)the Key Laboratory of Mariculture&Stock Enhancement in North China’s Sea,Ministry of Agriculture,P.R.China(No.2014-MSENC-KF-01)+1 种基金the Natural Science Foundation of Hainan Province(No.20163054)the Special Scientific Research Funds for Central Non-profit Institutes,Yellow Sea Fisheries Research Institutes(No.20603022015011)
文摘Cnidarians, being regarded as ‘basal' metazoan animals, are considered to have relatively high plasticity in terms of sex reversal. In this study we used an experimental approach to demonstrate sexual diff erentiation and plasticity in benthic polyps and pelagic medusae of A urelia sp.1 maintained at dif ferent temperatures. Results indicated that in A urelia sp.1, sex diff erentiation has been determined at the polyp stage and that all medusae originating from a given polyp are, phenotypically, of the same sex. In addition, the sex of polyps budding from the same clone(either male or female) at dif ferent temperatures appears to be the same as that of the parent. The sex of medusae that had originated from a known-sex polyp was observed to remain the same as that of the parent, irrespective of differences in strobilation or rearing temperatures. These results indicate that the mechanism of sex determination of Aurelia sp.1. is not influenced by prevailing temperature regimes. A comparison of variability in terms of sexual plasticity of A urelia sp.1 with that of Hydrozoa and Anthozoa suggests that species characterized by a free-swimming medusa life stage have a high dispersal potential, which probably results in a lower rate of sex reversal.
