Effects of diatoms on reproduction and growth of marine copepods

Two hot spots in marine ecology, deleterious effects of diatoms and feeding selectivity of copepods, as well as new progress on these two issues achieved in the recent ten years, are reviewed. These two issues are considered correlated closely. Diatoms and their metabolites can induce deleterious effects on growth, reproduction and development of copepods, including increase of mortality and decrease of egg production, hatching and growth rates. Such negative effects, resulting from either chemical toxin or nutritional deficiency, can be conquered in natural environments by diverse feeding. It is therefore concluded that deleterious effects of diatoms observed in laboratory or during blooming period are only a special case that accommodation of feeding strategy of copepods is disabled. To understand their feeding strategy in natural environments is a prerequisite to explaining the mechanisms of deleterious effects caused by diatoms, and makes it possible to re-evaluate the energy flow in marine ecosystems.     

广西红树林生境底栖硅藻的种类

1992年6月和11月,于广西两个红树林区采集了红树植物茎部附着物,立地土壤,潮沟土壤和腐叶的底栖硅藻样品。共鉴定出159个种和变种,其中有4个种是我国的新记录。大多数样品中卵形藻、双眉藻和曲壳藻等属的细胞较多。具槽直链藻是红树植物茎表的主要附生种类。     

利用化石群分异度探讨古水深

古水深的确定是长期未解决的难题,同时也是急需解决的问题。化石群分异度的研究为确定古水深提供了一种新方法。本文通过多方面研究,证实了信息函数与优势度两种分异度与水深之间存在着密切的关系,并利用该关系估算出东营盆地沙三晚期的水体深度范围。     

乌江上游筑坝蓄水后各水库浮游硅藻及浮游动物群落生态特征

对乌江上游11个水库24个点进行4次采样,在样品分析中共记录到浮游硅藻77种,隶属于2纲7目9科21属;浮游动物71种,其中轮虫10属25种,占总种数的35.21%;枝角类10属23种,总种数的32.39%;桡足类11属23种,占总种数的32.39%。调查结果显示乌江上游各湖泊水库的浮游硅藻及浮游动物的群落多样性低,特别是乌江渡水库及偏岩河河段,在2008年4月份以华丽星杆藻(Asterionella formosaHassall)为主酱油色的水体,为轻度硅藻水华,浮游硅藻及浮游动物的多样性最低。各水库中的浮游硅藻主要优势种为小环藻属(Cy-clotollakutzing)、尖针杆藻(Syneder acuskuetzing),华丽星杆藻(Asterionella formosaHassall),并呈季节性的交替变化;浮游动物主要是轮虫(Keratella cochlearisGosse)密度变化最为明显,枝角类(Cladocera)、桡足类(Copepo-da)变化不明显。     

相干态光场与耦合双原子系统中光子的统计性质

采用全量子理论和数值计算方法求解了旋波近似下相干态光场与耦合双原子相互作用的系统波函数,分析了原子的初始状态和原子间偶极偶极相互作用Ω对光子统计性质的影响.数值计算结果显示:原子间偶极偶极相互作用Ω对光子的超泊松分布效应无明显影响,但崩塌-回复周期却随Ω的增大而减小,近似成反比关系;系统初始状态对光子的超泊松分布效应有明显影响,而对崩塌回复周期无影响.     

泸沽湖硅藻植物初报

泸沽湖是中国第三大深水湖,属典型的高原湖泊,其湖盆形态复杂,多半岛、岛屿与岬湾,生境多样性高,透明度高达12.5 m,水质达国家地表水Ⅰ类标准.对泸沽湖硅藻植物进行了全面调查,共鉴定出111个硅藻分类单位,包括103种8变种,隶属于2纲6目10科51属,其中中国新记录2属2种,分别为:微小暗额藻(Aneumastus ...     

Seasonal cycles of abundance of the flora and fauna associated with Cladophora albida (Huds.) Kütz in rockpools

Seasonal data for one year on the flora and fauna associated with Cladophora albida (Huds.) Kütz from four rockpools (3 high-shore, 1 mid-shore) on Great Cumbrae Island, Firth of Clyde, Scotland are presented. A total of 131 858 animals was censussed. The mid-shore pool had a significantly lower annual mean density than the high-shore pools. Only at the most exposed site was a distinct seasonal trend apparent (lowest faunal density in spring, highest in summer). Species number showed no marked seasonal fluctuations neither did equitability. The lowest diversity was found in the mid-shore pool. Epiphytic cyanobacteria were present throughout the year. Diatoms were absent in the summer; possibly because of intense grazing by meiofaunal herbivores. The reduction in overall faunal density in the mid-shore pool was caused by the absence of large numbers of nematodes at this site related to the reduced availability of detritus and sand grains, perhaps reflecting greater wave scouring at this level on the shore. Large meiofaunal populations overwinter successfully in Cladophora in these ice-free latitudes and sheltered waters. Nematodes and harpacticoid copepods dominate the fauna of Cladophora in these permanent pools. Even populations in high-shore situations are remarkably stable. The rhombognathid mites, the polychaetes Fabricia sabella and Janua pagenstecheri and the chironomid larvae all showed little or no seasonal fluctuations in numbers, though most harpacticoid copepods, ostracods, turbellarians and archiannelids had very definite population maxima. Cladophora also acts as a nursery ground for species whose adults live elsewhere on rocky shores.     

A new genus and species of Cixiidae (Homoptera: Fulgoroidea) from Lower Cretaceous amber

Mundopoides aptianus gen. et sp. nov. (Homoptera: Fulgoroidea: Cixiidae) is described on the basis of a fossil of an adult female preserved in Lebanese amber of Lower Cretaceous (Aptian) age, and is compared with modern genera.     

辽宁省千山春季和初夏硅藻的初步研究

报导了1.辽宁千山藻类中,硅藻是优势种,计有108种及变种.其中,中心纲2个属5个种及变种,羽纹纲22属103种及变种.2.千山有典型寒冷山区冷水性藻类种类.3.通过对三种生态类型中的硅藻进行比较,附着藻类中,硅藻是优势种.4.小环境因素明显影响藻类的分布.     

河南西峡蛋化石群的保护与对策研究

河南西峡地区垩纪蛋白化群分布广泛，埋藏集中，层位多，数量大，类型多样，保存完好，在中国及世界上具有独特的科学价值。在《世界遗产名录》与《全球地质及古生物遗址名录》中，迄今尚无一例蛋化石遗址，西峡蛋化石群符合世界自然遗产的评估标准，理应被列入《世界遗产名录》。上前应加强保护与研究，并积极开展世界自然遗产的申报工作。