埃迪卡拉纪晚期高家山生物群中瓶状微化石新材料

高家山瓶状微化石为一类发现于陕南宁强高家山生物群Conotubus-Gaojiashania-Protolagena组合带中的微体化石。借助扫描电子显微镜对高家山瓶状微化石的形态特征进行观察,发现在瓶状微化石外壳表面具有浅坑与水滴状构造;运用阴极发光技术研究化石壳壁结构和壳腔内部结构,发现一个瓶状微化石内部存在球状构造。这些化石新材料中的微构造不仅丰富了我们对高家山瓶状微化石形态的认知,还加深了我们对前寒武纪原生生物演化的理解。     

一种硅藻中国新记录属种——科氏杜氏藻

科氏杜氏藻是一种泥生或附沙生硅藻。该文对最近刚确立的一个硅藻属——杜氏藻属进行了介绍,利用光学和扫描电子显微镜对2019年4月20日采自东洞庭湖国家级自然保护区的科氏杜氏藻标本进行了观察研究。结果表明该标本具有以下主要形态特征:(1)壳面椭圆披针形。(2)中央区为蝴蝶结形,没有延伸至壳缘。(3)线纹在壳面大部分区域呈辐射状排列,在两端近平行排列,中部线纹密度20~22条/10μm。(4)孔纹圆形或近圆形,在内壳面被圆顶状的孔膜覆盖。(5)在壳面两端存在假隔片。该文调查采集的科氏杜氏藻种群的形态特征与模式种群相吻合,该属在中国是首次报道,为中国新记录属。     

硅藻中国新记录种——沃氏具脊桥弯藻

本研究利用光学和扫描电子显微镜对采自湖南省江华瑶族自治县一源头水溪流的硅藻标本进行了观察,鉴定出中国新记录一种：沃氏具脊桥弯藻(Oricymba voronkinae Glushchenko, Kulikovskiy & Kociolek)。研究结果显示该具脊桥弯藻具有以下鉴别特征：(1) 壳面呈披针形,末端钝圆;(2) 壳面平坦,壳面和壳套区别明显,被一条边缘脊分开;(3) 边缘脊两侧具凹槽;(4) 近缝端向壳面腹侧偏转,远缝端几乎呈直角向壳面背侧弯曲且在远缝末梢的背侧处有一个缺刻;(5) 壳面中央孤点外侧开口为一个简单圆形,内壳面开口为被向内生长物所遮挡的两个裂缝;(6) 壳面孔纹呈裂缝状,仅近中轴区的孔纹呈半圆至弧形;孔纹的开口被齿状突出物部分遮挡;(7) 顶孔区内侧开口被波浪形的贯壳列硅质条所覆盖但未完全封闭内侧开口;(8) 壳面中部的线纹密度为8～11条/10 μm,孔纹密度25～30个/10 μm。本文提供了沃氏具脊桥弯藻孔纹密度和原始描述中未揭示的顶孔区内壳面的详细超微结构特征。     

硅藻中国新记录种——帕瓦拉桥弯藻

在对湖南省硅藻多样性研究过程中,发现其中一采自湘江的桥弯藻种类具有以下鉴定特征：(1)细胞小,长度小于29μm;(2)壳面略微呈背腹之分;(3)远缝端末梢向壳面背侧弯曲;(4)顶孔区很小,由1～3横列形态不同的两种类型孔纹组成,一种孔纹与壳面上的孔纹相似,呈狭缝隙状,另一种为圆形小孔,其内部开口上方有袋盖状硅质突出物覆盖;(5)壳面背侧中部处线纹密度每10μm为10～12条、腹侧中部处每10μm为11～13条,孔纹密度每10μm为30～40个;(6)在靠近壳面腹侧中央区具有1～2个孤点。经与帕瓦拉桥弯藻(Cymbella pavanaensis A. Vigneshwaran et al.)模式种群相比较,该文确定上述桥弯藻即为帕瓦拉桥弯藻。该文提供了对帕瓦拉桥弯藻超微结构的更多清晰认识,扩大了其地理分布区域,且是该种在中国的首次报道。     

中国茨藻科植物种皮微形态特征及其系统学意义

本文应用扫描电镜对国产茨藻科植物的外种皮和内种皮微形态特征进行了研究,结果表明茨藻科植物在种子表面细胞形态、表面纹饰和内种皮内层细胞形态及小瘤状突起的大小和密度等方面存在差异,可作为种级水平分类的依据,并首次发现外种皮微形态特征也与内种皮内层小瘤状突起一样具有重要的系统学意义。根据种皮微形态特征的研究结果,我们支持Miki(1937)和Shaffer-Fehre(1991b)等关于茨藻科与水鳖科近缘,而不应放在眼子菜目的观点。对弯果茨藻Najas ancistrocarpa A．Br．ex Magnus和草茨藻N.graminea Del.外种皮的研究结果表明其外种皮细胞表面具瘤状颗粒而非网状加厚。     

我国硅藻类的新记录属--微舟藻属及其一新种

利用透射电镜对采自东黄海海域典型站位的微型硅藻(nanodiatom,〈20μm)进行了研究.观察到我国微型硅藻类的一个新记录属:微舟藻属Nanoneis R.E.Norris以及该属的一个新种:长微舟藻Nanoneislongta sp.nov..该属的主要特征是:壳面两侧对称,具有不完全壳缝,壳面除中轴区外都有横肋纹或长室孔分布.本文描述该属的两个种,其中海斯微舟藻(Nanoneis hasleae R.E.Norris)为我国的新记录种,长微舟藻为新种,两种之间主要的区别特征是壳面外形、长宽比例以及壳面横肋纹的密度.并较详细地描述了该属种类的分类特征、生态习性和分布.     

我国硅藻类的新记录属——微舟藻属及其一新种(英文)

利用透射电镜对采自东黄海海域典型站位的微型硅藻(nanodiatom,<20mm)进行了研究。观察到我国微型硅藻类的一个新记录属微舟藻属NanoneisR.E.Norris以及该属的一个新种长微舟藻Nanoneislongtasp.nov.。该属的主要特征是壳面两侧对称,具有不完全壳缝,壳面除中轴区外都有横肋纹或长室孔分布。本文描述该属的两个种,其中海斯微舟藻(NanoneishasleaeR.E.Norris)为我国的新记录种,长微舟藻为新种,两种之间主要的区别特征是壳面外形、长宽比例以及壳面横肋纹的密度。并较详细地描述了该属种类的分类特征、生态习性和分布。     

中国淡水硅藻新记录——偏肿内丝藻兴凯变种

于2016年5月对浙江省仙居国家公园进行藻类多样性调查时,发现了中国淡水硅藻的1个新记录种——偏肿内丝藻兴凯变种[Encyonema ventricosum var.hankensis(Skvortzov) RodionovaPomazkina]。该文采用光镜和扫描电镜对偏肿内丝藻兴凯变种浙江种群的形态特征进行了观察和描述,并将其与该种的其他地理种群及内丝藻属其他相似物种的形态特征进行比较,同时讨论了该物种的生境特征。结果表明:(1)偏肿内丝藻兴凯变种壳面均具明显背腹之分,背缘明显拱起,腹缘轻微波曲;端部呈头状至喙状。(2)偏肿内丝藻兴凯变种浙江地理种群在背部中央区域具一孤点,而其兴凯种群对孤点这一特征未有描述。(3)偏肿内丝藻兴凯变种在俄罗斯的兴凯湖和贝加尔湖等地有分布,该种在中国是首次报道。     

东北地区蒲公英属瘦果微形态特征及其分类学意义

通过对东北地区10种蒲公英瘦果形态及微形态特征进行观察比较,为蒲公英属（Taraxacum F.H.Wigg.）分类研究提供瘦果形态学证据。利用体式数码光学解剖镜和电子探针显微镜,对蒲公英瘦果进行观察比较,并根据瘦果大小、形状、喙基比例、颜色及微形态表面纹饰特征进行聚类检索。结果表明,（1）瘦果微形态特征为全身具刺,具白色斑点,刺状突起成行且规则排列,但刺大小及密度存在显著差异;（2）检索结果表明,以蒲公英瘦果形态及微形态特征进行检索的结果与《中国植物志》中的分类结果一致。该实验通过对东北地区10种蒲公英瘦果形态及微形态特征进行描述,确定了蒲公英瘦果形态特征差异可作为分类学表征证据,并将喙基长度（B）与瘦果长度（A）（不包括喙基长）之比命名为喙基比（B/A）,该比值可增补为分类要点。研究结果支持《中国植物志》中对蒲公英属的分类结果。     

古尔班通古特沙漠生物结皮微鞘藻分类学研究

实验研究了从古尔班通古特沙漠生物土壤结皮中分离纯化培养出的11株与微鞘藻(Microcoleus)形态接近的丝状蓝藻,通过形态特征、16S rRNA和ITS二级结构相结合的多相分析方法对其进行分类学研究。研究结果表明,实验藻株隶属于微鞘藻科(Microcoleaceae)的微鞘藻属(Microcoleus)和束脉藻属(Symplocastrum),其中包括2个中国新记录种:斯坦微鞘藻(Microcoleus steenstrupii)和细长束脉藻(Symplocastrum flechtnerii),另外还有具鞘微鞘藻(Microcoleus vaginatus)和类似斯坦微鞘藻的存疑物种。藻丝多少与排列方式、细胞大小与末端细胞形状,以及16S rRNA系统发育位置是确定微鞘藻(Microcoleus)与束脉藻(Symplocastrum)属于不同物种的关键依据, ITS二级结构是区分属内不同物种的重要参考。     

Gogorevia,a New Monoraphid Diatom Genus for Achnanthes exigua and Allied Taxa (Achnanthidiaceae) Described on the Basis of an Integrated Molecular and Morphological Approach

A new diatom genus, Gogorevia, is described on the basis of an integrated molecular and morphological investigation. Two species are described from Vietnam: the generitype, G. rinatii sp. nov., and G. ovalis sp. nov. These species share many morphological features with Achnanthes exigua and allied taxa that were previously transferred to the genera Achnanthidium or Lemnicola. Our current molecular investigation shows that Gogorevia is distinct and phylogenetically removed from the above-mentioned genera. Morphologically, Gogorevia differs from Achnanthidium and Lemnicola by the shape of the valves, possessing uniseriate striae, raphe morphology, and the presence of an evident sternum. The recently described species Lemnicola uniseriata is transferred to Gogorevia on the basis that it possesses the same morphological features and phylogenetic position as other members of the genus.     

Diatoms of Dindifelou fall (upper Basin of the Gambia River,Senegal): floristic inventory

The Dindifelou fall, located in south‐eastern Senegal, receives its water from discharging springs located in Dande plate‐land. These waters form, at the foot of the cliff, a pond that drains into the Thiokoye, a tributary of the Gambia River. The water quality of the pond and the stream is very good based on physicochemical analyses. Around the pond region, a microclimate characterized by a higher humidity and a lower temperature compared with the surrounding area is present. Diatoms study is carried out in different habitat types associated with this fall. The samples were taken by scraping the surface of rocks and rinsing fern leaves with sparkling water. Dande plate‐land is made of Upper Proterozoic sandstones whose gravity accumulations litter the bottom of the pond and the stream. This study allowed us to inventory 61 species and varieties of diatoms belonging to 28 genera. The most represented genera are Achnanthidium (ten species), Eunotia and Pinnularia (eight species each). Twelve species and varieties are reported for the first time in Senegambia including five of the genera Achnanthidium. The microflora is dominated by Achnantidium minutissimum and Achnanthidium catenatum, followed by Ulnaria ulna and various species of the genera Eunotia and Brachysira. Aerial habitats are more diversified here than the epilithic samples.     

<Emphasis Type="Italic">Prorocentrum vietnamensis</Emphasis> sp. nov. (Prorocentraceae Dinophyta): A new armored dinoflagellate from Vietnam coastal waters

TheProrocentrum species, which are primarily marine, are distributed worldwide and occur in ocean, neritic, and littoral environments.Prorocentrum is either a planktonic or benthic genus, with some species possibly being both. Until now, about 35 species had been reported including two that are fresh-water. Some species contain toxic substances. As one of many currently active studies, we collectedP. vietnamensis sp. nov. from Hon Mé, Gulf of Tongkin, Vietnam. Based on its cell shape, smooth valve surface, arrangement of valves and marginal pores, plus characteristics of the central pyrenoid, we propose thatP. vietnamensis is a new species. Its attributes include straight cell sides that are parallel to each other, as well as anterior and posterior areas with rounded ends that form a short, rod-shaped cell that is unique to this species.     

3种淡水布纹藻(硅藻纲)的超微结构研究

该研究利用光学和扫描电子显微镜对3种淡水布纹藻(钝布纹藻、库氏布纹藻和赛欧托布纹藻)的形态学进行了研究,以明确它们的精细结构特征;并分析讨论它们在中国的地理分布区域。结果表明：(1) 3种淡水布纹藻皆属于粗糙布纹组;从壳面观看,都具有S形和反S(S)形两种壳瓣外形。(2) 钝布纹藻具有弱的S形壳面外形、T形的外近端壳缝末稍和直的内近端壳缝末稍以及椭圆形的中央区;库氏布纹藻具有明显的S形壳面外形、略微向不同侧偏转的外近端壳缝末稍和直的内近端壳缝末稍以及椭圆形的中央区;赛欧托布纹藻具有弱的S形壳面外形、强烈钩状的外近端壳缝末稍和T形的内近端壳缝末稍以及倾斜的中央区。(3) 钝布纹藻在广东、广西、湖南、四川和云南等地有分布;库氏布纹藻在新疆和湖南等地有发现;赛欧托布纹藻分布于武陵山区,该文是其在中国淡水分布的首次报道。     

Kulikovskiyia gen. nov. (Bacillariophyceae) from the lateritic rock pools of the Western Ghats,India and from Hainan Province,China

A new triundulate naviculoid diatom genus is described from the Western Ghats of Peninsular India and Hainan Province, China. The new taxon, Kulikovskiyia gen. nov. has robust conical spines along its margin and at the apices and the external valve face has longitudinally‐oriented siliceous slat system extending the length of the valve. The external distal raphe ends bifurcate and terminates on the valve face. There appear to be superficial similarities between this Asian genus and species and Playaensis, a genus comprised of two species found only in the western USA. The systematic position of Kulikovskiyia is discussed, and other than noting its similarities to other biraphid naviculoid diatoms due to symmetry features and the position of the raphe, we are uncertain about its systematic placement at finer levels of classification.     

Wind‐driven thermocline movements affect the colonisation and growth of Achnanthidium minutissimum,a ubiquitous benthic diatom in lakes

相似文献   

Morphology and taxonomy of Cyclotella tasmanica spec. nov,a newly described diatom from Tasmanian lakes

A species of Cyclotella with an elliptical valve outline has been found in several Tasmanian lakes and is herein described and named C. tasmanica nov. sp. Morphologically, it is similar to C. stelligera and, to a lesser extent, to C. radiosa. The valve has coarse, clearly alveolate, marginal striae and a central rosette. Unlike other elliptical forms, the central area is always more or less circular. The nearest similar species is C. rhomboideo-elliptica.     

Arecophila bambusae sp. nov. andA. coronata comb. nov., from dead culms of bamboo

A new species ofArecophila and a species previously known asAmphisphaeria coronata are described and illustrated from dead culms of bamboo.Arecophila bambusae sp. nov. is distinct in the genus in having ellipsoidal ascospores with slightly round ends, and asci with a narrow subapical ring.Arecophila coronata comb. nov. has asci with a wedgeshaped apical ring and weakly striated ascospores enclosed in wide mucilaginous sheath.     

Observations on the valve structure of marine species of the diatom genus Cocconeis Ehr.

The valve structure of three marine diatom species, Cocconeis molesta var. crucifera, C. dirupta and C. pellucida was studied by transmission and scanning electron microscopy. In all Cocconeis examined, the areolae are occluded by hymenes located near the internal openings in the raphid valve and near the internal openings in the araphid valves.     

Morphological variability of the diatom Cyclotella atomus Hustedt var. atomus and C. atomus var. gracilis var. nov.

Cyclotella atomus collected from different rivers, reservoirs and lakes shows considerable morphological variability. On the basis of electronmicroscopic (EM) study, we propose Cyclotella atomus var. gracilis Genkal et Kiss as a new variety of this species. Cyclotella atomus var. atomus has short and long radial striae, which are irregularly arranged on the same valve, and the alveolar chambers are not clearly divided from the central, hyaline part of the valve face. In addition to the described basic form, several specimens with other features have also been found and are thought to belong to an undescribed variety. The striae of the new variety are equal in length, and the alveolar chambers are clearly divided from the hyaline central area of the valve face by a curved structure.There are EM micrographs on Cyclotella atomus var. gracilis under different names in different papers. The new variety has several characteristics also found in other species, e.g. Cyclotella caspia Grun., or C. meneghiniana Kütz.