双壳缝硅藻中国2新记录种——肿胀类辐节藻和英格兰盘状藻具孤点变种

该研究利用光学和扫描电子显微镜,对采自东洞庭湖国家自然保护区的2种双壳缝硅藻中国新记录种——肿胀类辐节藻和英格兰盘状藻具孤点变种的标本进行了详细形态学研究。观察发现：(1)肿胀类辐节藻具有4个鉴定特征：①壳瓣轮廓在大的标本中呈披针形,在小的标本中呈椭圆披针形;②线纹在壳面中部呈辐射状排列,彼此间隔相对较宽;③假隔片在壳面两端都存在;④ 孔纹在内壳面被具微孔的膜完全覆盖。(2)英格兰盘状藻具孤点变种也具有4个鉴定特征：①壳瓣线性椭圆形或椭圆形;② 线纹除了在壳面两端呈平行排列外,在壳面大部区域呈辐射状排列,中部线纹密度10～14条/10 μm;③在壳面中央有一个孤点;④孔纹内部开口被由4个支柱支撑的孔板所覆盖,孔纹密度35～40个/10 μm。该研究的详细描述和清晰的插图为肿胀类辐节藻和英格兰盘状藻具孤点变种的准确鉴定提供了参考。     

中国硅藻1新记录种——喙状比利牛斯山微小曲壳藻

利用光学和扫描电子显微镜对采自武陵山区澧水的1种中国新记录硅藻——喙状比利牛斯山微小曲壳藻进行了形态研究。该种的鉴定特征为壳面线形披针形,具有喙状的末端,有壳缝壳面末端线纹呈略微会聚状或近平行排列,孔纹膜为筛状。该研究结果扩展了对喙状比利牛斯山微小曲壳藻形态结构和地理分布的认识。     

中国淡水硅藻新记录——瓦维洛夫双肋藻北大核心CSCD

2021年1月,对福建省莆田市东圳水库进行藻类多样性调查时,发现了中国淡水硅藻的一个新记录种———瓦维洛夫双肋藻(Amphipleura vavilovii Glushchenko&Kulikovskiy)。该种在老挝Namlik村的河流中首次被报道,但未提供其外壳面扫描电镜照片和形态描述。该研究应用光镜和扫描电镜对采集自中国福建的瓦维洛夫双肋藻种群的形态特征进行了观察和描述,并将其与双肋藻属模式种及其他相似种的形态特征进行了比较。结果表明:(1)瓦维洛夫双肋藻壳面线形披针形,中部平行或略收缩,朝向两端渐窄,末端钝圆。(2)中央胸骨明显,朝向两端分叉形成两条平行硅质肋。(3)线纹单列,在10μm内有25~30条。该研究结果与瓦维洛夫双肋藻模式种群形态、线纹等特征吻合,该种在中国是首次报道。     

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.     

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。     

明晰双肋藻(硅藻门)的超微结构研究北大核心CSCD

在对武陵山区硅藻分类和多样性研究中,收集到了一种双肋藻的标本,经研究鉴定,其为明晰双肋藻[Amphipleura pellucida(Kützing)Kützing]。光学显微镜观察和扫描电子显微镜观察结果表明:明晰双肋藻具有以下特征:(1)纺锤形的壳瓣外形。(2)长而直的中央胸骨。(3)仅着生在靠近壳面两端的短壳缝系统。(4)线纹密度为38~39条/10μm,孔纹密度为54~58个/10μm。(5)壳缝的外近缝端呈直线状,远缝端略微膨大。(6)孔纹内侧开口被圆形筛膜覆盖。该研究结果为明晰双肋藻提供了清晰的超微结构图片资料以及科学的描述。     

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。     

中国硅藻化石新种和新记录种

在对江汉平原钻孔中的化石硅藻进行鉴定时,发现1个新种类：江汉异极藻（新种）Gomphonema jianghanensis sp.nov.,该种的主要特征为：壳面狭披针形或线性披针形,端部和基部圆形,中轴区窄。中心区宽呈横矩形,在紧靠中心区的一侧具1条很短的线纹,另一侧有时有1条很短的线纹,有时没有线纹,无孤点。壳缝呈直线,在中央区附近略弯向一侧,在极节处折向另一侧。线纹轻微放射状,中部略弯曲,在近顶端处没有线纹,在10μm内,中部具6—13条。长20—30μm,宽4—7μm。4个中国新记录属：楔异极藻属Gomphosphenia Lange-Bertalot、楔月藻属（新记录属）Cymbopleura Krammer、优美藻属Delicata Krammer、尖月藻属Encyonopsis Krammer,8个中国新记录种：微小异极藻Gomphonema minutiforme Lange-Bertalot＆Reichardt、较细楔异极藻Gomphosphenia tenerrima（Hustedt）Reichardt、舌状楔异极藻Gomphosphenia lingulatiforme（Hustedt）Lange-Bertalot、瑞克舟形藻Navicula rakowskae Lange-Bertalot、北方羽纹藻岛屿变种Pinnularia borealis var.islandica Lange-Bertalot,舟形盖斯勒藻Geissleria tectissima（Lange-Bertalot）Lange-Bertalot＆Metaeltin、岩生楔月藻小变种Cymbopleura rupicola var.minor Krammer和法国尖月藻Encyonopsis falaisensis（Grunow）Krammer,1个种的补充说明：中华优美藻Delicata sinensis Krammer ＆ Metzetin。     

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。     

硅藻中国一新记录种——泉生平片藻

利用光学显微镜和扫描电子显微镜对采自湖南省绥宁县巫水水域的硅藻标本进行了观察研究,鉴定出其中一种为硅藻中国新记录种——泉生平片藻［Tabularia fonticola (Hustedt) C.E. Wetzel & D.M. Williams］,该种具有以下鉴别特征：(1) 壳面轮廓为线形披针形,中央胸骨宽,线纹短且宽。(2) 横主肋和纵细肋硅质化增厚。(3) 孔纹开口被数条横向硅质条组成的筛板所遮拦。(4) 每个壳面仅在其一端着生一个唇形突。(5) 壳套顶孔区孔纹有序排列。(6) 第一环带开放。该研究首次报道了泉生平片藻的前正常营养期细胞的超微结构特征,研究结果不仅增加了对泉生平片藻的超微结构认识,而且扩展了其地理分布区域。     

管壳缝类硅藻中国新记录属种——非洲南氏藻

利用光学和电子显微镜对采自黄海水域的1个管壳缝类硅藻——非洲南氏藻进行了形态学研究,并对其地理分布进行了讨论.结果表明:(1)该种壳体带面呈矩形,壳面窄椭圆形,具有钝圆的末端.(2)壳缝居中,由两条等长的分支组成.(3)管壳缝由复杂、接合的肋突支撑,但无龙骨.(4)每条线纹仅有1个孔纹,壳套上最多有1列孔纹.(5)目前...     

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.     

New freshwater diatom genus,Edtheriotia gen. nov. of the Stephanodiscaceae (Bacillariophyta) from south‐central China

We describe a new genus and species of the diatom family Stephanodiscaceae with light and scanning electron microscopy from Libo Small Hole, Libo County, Guizhou Province, China. Edtheriotia guizhoiana gen. & sp. nov. has striae across the valve face of varying lengths, and are composed of fine striae towards the margin and onto the mantle. Many round to stellate siliceous nodules cover the exterior of the valve. External fultoportulae opening are short tubes; the opening of the rimportula lacks a tube. Internally a hyaline rim is positioned near the margin. Marginal fultoportulae possess two arcuate opercles. Areolae have domed cribra on the valve face. Those near the margin do not open to the interior. One to three sessile to slightly‐raised rimportulae are placed on the valve face towards the margin; they do not terminate shortened striae towards the center of the valve. This suite of features distinguishes this group from other known genera in the Stephanodicaeae. Cyclotella shanxiensis is transferred to Edtheriotia, making the new combination E. shanxiensis (Xie & Qi) Kociolek et al. comb. nov. It differs from E. guizhoiana by the presence of open pores near the margin of the valve. Features of the new genus are compared and contrasted with others in the Family Stephanodiscaceae. The two species of the genus, unlike most in the family, are known only from rivers and ponds from China and Japan.     

Valve morphogenesis in an araphid diatom Rhaphoneis amphiceros (Rhaphoneidaceae,Bacillariophyta)

The pattern centre in valve morphogenesis is an annulus in centric diatoms or a sternum in pennate diatoms. The genus Rhaphoneis is currently placed within a lineage that diverges at the root of the pennate diatom clade in most molecular phylogenies, and its valves have a unique pattern to their striae, i.e. radiating from both apices, giving the impression that a pattern centre exists at both ends of the valve and virgae (ribs) formation proceeds centripetally. The present study, however, shows that the pattern centre is actually a linear sternum and the formation of virgae proceeds centrifugally, a pattern centre that is commonly found in most araphid diatoms. Thus, the hypothesis that valve morphogenesis based on a linear sternum and perpendicular virgae is a synapomorphy of pennate diatoms is supported. Our study also demonstrates that the pattern of valve formation can be observed by light microscopy with a direct mounting method when the specimen is relatively large, i.e. exceeding approximately 50 µm in valve length. An important advantage of the use of the direct mounting method is that it requires no repeated centrifugation steps for dehydration, steps necessary for observation by a scanning electron microscope, causing the loss and/or collapse of the specimen, particularly with fragile valves in the early stages of development.     

山西省盐池硅藻一新种

运城菱形藻 新种 图版1,图1—10 Nitzschia yunchengensis Xie et Li, sp. nov. Frustula e facie connexionis rectangularis, angulis rotundatis, marginibus in mediomodice concavis, axibus pervalvaribus 9. 3—10. 03μm altis, copulis multis. Valvae lineares,     

Description of Conticribra tricircularis,a new genus and species of Thalassiosirales,with a discussion on its relationship to other continuous cribra species of Thalassiosira Cleve (Bacillariophyta) and its freshwater origin

A new diatom genus Conticribra is erected to accommodate C. tricircularis, described from a freshwater Pliocene deposit in Trout Creek, Oregon (USA). The genus accommodates species possessing: (i) loculate areolae with (semi-) continuous cribra; (ii) non-plicated valve face; (iii) rimoportula located on the valve mantle, replacing a fultoportula. Conticribra tricircularis has no valve face fultoportulae and can easily be distinguished by its marginal fultoportulae with four satellite pores arranged in three rings. Three species are transferred to the new genus from Thalassiosira sensu lato. Using evidence from the fossil record and recent molecular data, a hypothesis concerning the freshwater origin of Conticribra is discussed.     

Trochus kotschyi, the first Indian Ocean record of the genus Osilinus (Mollusca: Gastropoda: Trochidae)

The species Trochus kotschyi Philippi, 1849, and Priotrochus obscurus (Wood, 1828) have been much confused in the past. Consistent differences between these taxa in respect of shell morphology, external anatomy and radular and opercular form are demonstrated. The distribution of T. kotschyi and the extent to which it and P. obscurus are sympatric are discussed. T. korschyi is referred to the genus Osilinus Philippi, 1847, a new combination and the first record of the genus from the Indo-West Pacific. The species is thought to be a pre-Miocene relict reflecting a mid-Tethyan origin of the genus. A note on the type species designation of Osilinus is provided.