Bacillariophyta diatoms pdf

Google Scholar 11 Krammer, K. Google Scholar 15 Lange-Bertalot, H. Google Scholar 16 Lange-Bertalot, H. Google Scholar 17 Lange-Bertalot, H. Google Scholar 18 Levkov, Z. Google Scholar 19 Levkov, Z.

Google Scholar 20 Potapova, M. Google Scholar 22 Reichardt, E. Google Scholar 23 Zakharova, V. Gabyshev Authors S. Genkal View author publications. View author publications. Ethics declarations The authors declare that they have no conflict of interest.

Additional information Translated by N. Rights and permissions Reprints and Permissions. About this article. Thus, N. Two diploid fusion cells or zygotes escape from the enclosing pustules.

They remain doranant for some time. Later the zygote elongates more in the longitudinal plane and functions as auxospore Fig. It may be secreted by the auxospore or by the remains of the zygotic membrane.

The auxospore secretes new pustules around itself around the perizonium. The reconstituted new cell is of normal size and after sometime begins to divide vegetatively to form new generations.

The valves of the old pustules are often seen attached to the newly formed pustules Fig. Top Menu BiologyDiscussion.

Classification of Bryophytes. This is a question and answer forum for students, teachers and general visitors for exchanging articles, answers and notes. Answer Now and help others. Answer Now. Here's how it works: Anybody can ask a question Anybody can answer The best answers are voted up and rise to the top.

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But opting out of some of these cookies may affect your browsing experience. Necessary Necessary. Figs 8, 12, Raphe filiform, straight. Proximal raphe ends slightly bent toward same side with drop-shaped central pores.

Distal raphe fissures sickle-shaped, deflexed to same side. Striae mostly curved, radiate at middle, gradually becoming convergent when approaching apices. Longitudinal lines absent. SEM: Valves linear with broadly rounded apices Figs 16, Central area hexagonal, reaching both margins Figs 17, 23 , or bordering both margins with a few short striae Figs 21, External proximal raphe ends bent in one direction, slightly dilated Fig.

Distal raphe fissures hooked towards same side Figs 16, 18, Internally, raphe branches straight, proximal raphe fissures curved towards same side, central nodule not raised Figs 22, 23 ; distal raphe terminating as helictoglossae Figs 24, Striae mostly composed of 4 rows of small areolae rarely 3 rows Figs 16—20 , covered by silicified plates Fig.

Qinghai province: Lake Qinghai, a sampling point near the lakeshore see Liu et al. Etymology:—Named after Lake Qinghai, where the species was found. Ecology:—The following environmental parameters were measured in the field: Electrical conductance Similar taxa: Pinnularia boliviana S. Pinnularia boliviana differs from P. Wetzel, Van de Vijver around the world considerably improved the genus et Ector, found that the species is widely distributed taxonomy Stancheva A remarkable Planothidium common taxa to improve the accuracy of diagnostic diversity was documented for the tropical region of tools that rely on diatom taxonomy and ecology.

Finally, South America e. Planothidium lagerheimii Cleve C. Wetzel et Ector Potapova ; Stancheva ; identified in previous studies either as Cocconeis rudis Wetzel et al. Gasse ; Cocquyt Frenguelli or Planothidium salvadorianum Hustedt et al. Kulikovskiy et al. Wetzel et S. Blanco et al. Novis et al.

Van de Vijver et al. Korsakova et al. Kaczmarska ; both light and scanning electron microscopy. This study describes a new monoraphid diatom Also, a large number of new fossil species have been species Planothidium scrobiculatum sp. Morphological comparison is conducted with , as well as in studies carried out on Baikal Lake the most similar taxa based on literature information. Khursevich et al. Kauffmann cm for diatom analysis. Isotype slides are deposited at the an age of 1.

Samples corresponding to depth of —77 cm and —11 cm were selected for this study for including Planothidium material, which were respectively dated at 1. See Ledru et al. Planothidium scrobiculatum, Marquardt et C. Wetzel A slice of sediment about 0. LM description: RV: Figs 1—18; SV: Figs 1—36 — Valves Afterwards, the cleaned material was repeatedly rinsed with lanceolate to elliptic—lanceolate with convex margins and distilled water to neutrality, and the oxidized material was cuneate apices, smaller valves sometimes with rounded mounted using Naphrax R.

Diatoms were examined apices Fig. Relative abundance was estimated by narrowly lanceolate. For SEM, analysis cavum. Areolae not discernible in LM. For the first one, subsamples of towards the central area. Central area is small, rounded, the oxidized suspensions were filtered and rinsed with addi- sometimes slightly asymmetric Fig. An ultra—high—resolution analytical field emission proximal raphe endings.

Striae radiate throughout the entire High—Technologies Corporation, Tokyo, Japan operated at 5 valve, never convergent near the apices, 12—13 in 10 kV and 10 mm distance was used for the analysis. Areolae are not discernible in LM.