Genetic diversity and population structure of spottedtail goby (Synechogobius ommaturus) based on AFLP analysis

Larval dispersal may have an important impact on genetic structure of benthic fishes. To examine population genetic structure of spottedtail goby Synechogobius ommaturus, samples from five different locations of China and Kunsan population in Korea were analyzed by using amplified fragment length polymorphism (AFLP) technology. A total of 253 bands were identified from 91 individuals by 5 primer combinations and the percentage of polymorphic bands was 43.87%. The average gene diversity was 0.0794 ± 0.1470 and Shannon’s information index was 0.1279 ± 0.2138. The pairwise F_st values ranged from 0.022 to 0.201. The results of AMOVA analysis indicated that 90.54% of the genetic variation contained within populations and 9.46% occurred among populations. The gene flow estimates (Nm) demonstrated that different gene flow existed among populations from 0.994 to 11.114. No significant genealogical branches or clusters were recognized on the UPGMA tree. The results support the hypothesis that larval dispersal ability can be responsible for the genetic diversity and population structuring.     

长江口东滩湿地斑尾刺虾虎鱼的栖息亚生境选择和食性差异

2015年7月至2016年6月每月在长江口东滩湿地西南水域的光滩、盐沼(以海三棱藨草为主)和潮沟3种亚生境进行斑尾刺虾虎鱼的样本采集,分析斑尾刺虾虎鱼的丰度和食性差异.结果表明:6—11月均采集到斑尾刺虾虎鱼样本,以幼鱼为主,其他月份未采集到.其中,7月采集数量最多,为71尾,11月仅采集到3尾.潮沟中共采集到93尾,分别是光滩和盐沼的5.2和4.9倍.6—11月斑尾刺虾虎鱼的平均体长和体质量均呈逐渐增加趋势.斑尾刺虾虎鱼主要摄食虾类、蟹类、昆虫类和多毛类等10大类30小类饵料生物.其中,虾类是最重要的饵料类别,并以安氏白虾等白虾属为主;蟹类以相手蟹属为主;昆虫类以小划蝽等蝽科昆虫成虫为主;鱼类饵料的质量百分比相对较高,但数量比例很低.不同亚生境斑尾刺虾虎鱼的饵料组成差异较大.7—11月斑尾刺虾虎鱼的摄食等级随体长增大而明显增大,秋末(11月)平均摄食等级可达3.不同亚生境间的斑尾刺虾虎鱼丰度差异与其摄食饵料不同有关.     

矛尾复虾虎鱼物种命名有效性探讨

利用形态学和遗传学方法探讨斑尾复虾虎鱼和矛尾复虾虎鱼的亲缘关系及矛尾复虾虎鱼物种有效性.研究结果显示:两种虾虎鱼在量度特征上存在极显著的差异,但分节特征不存在显著差异;与斑尾复虾虎鱼相比,矛尾复虾虎鱼头长相对较小,而尾鳍相对较长.对两种虾虎鱼的线粒体DNA控制区片段序列进行比较分析,得到两种虾虎鱼的遗传距离仅为0.006,与种内距离相当;NJ和MP法构建的系统树也显示两种虾虎鱼间亲缘关系很近,两种间不存在显著差异.综上,矛尾复虾虎鱼并非有效物种,应为斑尾复虾虎鱼的同种异名.     

全球气候变化对小兴安岭阔叶红松林影响的动态模拟研究

应用林窗模型(Forest Gap Model)及4种大气环流模式(General Girculation Models,GCMs) CO₂加倍"平衡响应"数值试验结果模拟了小兴安岭阔叶红松林对未来气候变化的动态响应过程.结果表明,在美国高达空间研究实验室(Goddard Institute for Space Studies,简记GISS)和美国俄勒冈州立大学(Oregon State University,简记OSU)GCMs预测的CO₂倍增未来气候情景下,与本底生物量(目前气候条件下)相比,阔叶红松林生物量逐渐升高,目前云冷杉阔叶红松林将逐渐向枫桦、紫椴和裂叶榆阔叶红松林演变;但在普林斯顿大学地球流体动力学实验室(Geophysical Fluid Dynamics Laboratory,Princeton University,简记GFDL)和英国气象局(United Kindom Meteorological Office,简记UKMO)GCMs预测的未来情景下,由于较大幅度的增温,云冷杉红松林将向以蒙古栎、紫椴和裂叶榆为主要树种的阔叶林演变.未来增温速率决定了阔叶红松林未来的演替方向.