Sellaphora davoutiana sp. nov.: a new freshwater diatom species (Sellaphoraceae, Bacillariophyta) in lakes of Northeastern France

During a floristic survey of freshwater lakes in the French Grand Est region, a new Sellaphora species (Bacillariophyceae) was found. Its morphology was examined in detail using light and scanning electron microscopy to formally describe it. Sellaphora davoutiana sp. nov. has elliptic-lanceolate valves with broadly protracted, subcapitate apices. Based on available literature, it is compared to morphologically similar species such as Navicula detenta, S. sardiniensis, S. sassiana and S. smirnovii. Valve dimensions, central area shape and striae density and pattern of this new species allow its separation from them. Sellaphora davoutiana has been found in three low-mountain lakes of glacial origin in Northeastern France, with watershed on granitic substratum. Additionally, illustrations of Hustedt type material of Navicula detenta are provided, and this taxon is formally transferred to the genus Adlafia.

Download Full-text

Encyonema bonapartei sp. nov.: a new freshwater diatom species (Cymbellales, Bacillariophyceae) in canals of Great East region (France)

Phytotaxa ◽

10.11646/phytotaxa.284.4.3 ◽

2016 ◽

Vol 284 (4) ◽

pp. 273 ◽

Cited By ~ 1

Author(s):

DAVID HEUDRE ◽

CARLOS E. WETZEL ◽

LUC ECTOR

Keyword(s):

Monitoring Program ◽

Central Area ◽

Similar Species ◽

Ventral Margin ◽

East Region ◽

European Water ◽

Northeastern France ◽

Physicochemical Data ◽

A New Species ◽

Freshwater Diatom

As a part of the Monitoring Program of the European Water Framework Directive, the phytobenthos of streams and canals was studied in the Great East region of northeastern France (French part of Rhine-Meuse river basin and Seine-Normandy basin). A new species, Encyonema bonapartei was identified in canals. Its morphology was examined in detail using light and scanning electron microscopy, which showed a unique combination of measurements and shape: valves are clearly asymmetrical and semi-elliptical to semi-elliptical-lanceolate with central area extended on ventral margin by shorter or missing striae. The striation is almost parallel with areolae indistinguishable in the light microscope. This paper provides comparison with morphologically similar species: Cymbopleura hustedtii, Encyonema brehmii, E. kalbei, E. marvanii, E. reichardtii and E. yuwadeeanum. Encyonema bonapartei was first discovered in the East Canal in 2014. It was then found in the Rhône-to-Rhine Canal and Champagne and Burgundy Canal in 2015. Most likely it will spread further in connected waterways. Information on its autecology is presented using the physicochemical data of the type locality.

Download Full-text

Fragilaria rinoi sp. nov. (Fragilariales, Fragilariophyceae) from periphytic river samples in Central Portugal

European Journal of Taxonomy ◽

10.5852/ejt.2016.248 ◽

2016 ◽

Cited By ~ 1

Author(s):

Cristina Delgado ◽

M. Helena Novais ◽

Saúl Blanco ◽

Salomé F.P. Almeida

Keyword(s):

Central Area ◽

River Basins ◽

Scanning Electron Micrographs ◽

Diatom Species ◽

Alkaline Ph ◽

Mean Values ◽

Central Portugal ◽

Lis River ◽

Scanning Electron ◽

Freshwater Diatom

A new benthic freshwater diatom, Fragilaria rinoi Almeida & C.Delgado sp. nov., is described from river periphyton samples in Portugal. Fragilaria rinoi sp. nov. is illustrated and discussed based on populations collected from the Vouga, Mondego and Lis river basins in central Portugal and compared with the type material of Fragilaria vaucheriae (Kütz.) J.B.Petersen. The morphological features of the new diatom species are documented through light and scanning electron micrographs, including a comparative analysis with related species of the genus (F. candidagilae Almeida, C.Delgado, Novais & S.Blanco, F. intermedia Grunow in Van Heurck, F. neointermedia Tuji & D.M.Williams, F. recapitellata Lange-Bert. & Metzeltin, F. perminuta (Grunow) Lange-Bert., F. vaucheriae and F. microvaucheriae C.E.Wetzel & Ector). Fragilaria rinoi sp. nov. is characterized by solitary cells without spines, lanceolate valves with slightly rostrate apices, a narrow, linear axial area, and a large, unilateral central area. Fragilaria rinoi sp. nov. may be confused with F. microvaucheriae in terms of length, striae density and outline, although a morphometric analysis revealed that F. rinoi sp. nov. is significantly wider. Fragilaria rinoi sp. nov. is present in rivers with high dissolved oxygen concentrations, medium to high conductivity, neutral to slightly alkaline pH and high mean values of nitrates and ammonium.

Download Full-text

Navicula daochengensis sp. nov., a new freshwater diatom species (Bacillariophyceae) from a small mountain lake, Sichuan Province, China

Phytotaxa ◽

10.11646/phytotaxa.439.2.6 ◽

2020 ◽

Vol 439 (2) ◽

pp. 150-158

Author(s):

TING WANG ◽

JIA-LIN WANG ◽

QI-CHAO ZHOU ◽

DMITRY A. CHUDAEV ◽

J. P. KOCIOLEK ◽

...

Keyword(s):

New Species ◽

Nature Reserve ◽

Sichuan Province ◽

Mountain Lake ◽

Morphological Description ◽

Similar Species ◽

Scanning Electron Micrographs ◽

Diatom Species ◽

Scanning Electron ◽

Freshwater Diatom

In this study, we describe a new freshwater diatom, Navicula daochengensis sp. nov., which was found in a small mountain lake, Lake Congqiancuo, Haizishan Nature Reserve, Daocheng County, Sichuan Province, China. The detailed morphological description of the new species is provided from light and scanning electron micrographs. Navicula daochengensis has a narrowly lanceolate valve outline with broadly-rounded ends. The striate are radiate and convergent to the apices. This new species is compared with similar species, such as Navicula elongata, N. venerablis, N. moralesii and N. radiosa, which differ in size, valve shape, striae density and ultrastructure.

Download Full-text

Encyonopsis neerlandica, a new freshwater diatom species (Bacillariophyta) from moorland pools in The Netherlands

Phytotaxa ◽

10.11646/phytotaxa.66.1.7 ◽

2012 ◽

Vol 66 (1) ◽

pp. 43

Author(s):

BART VAN DE VIJVER ◽

GEURT L. VERWEIJ ◽

JAKO VAN DER WAL ◽

ADRIENNE MERTENS

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

The Netherlands ◽

Similar Species ◽

Diatom Species ◽

Weakly Convex ◽

Valve Margin ◽

Moorland Pools ◽

Scanning Electron ◽

Freshwater Diatom

A new cymbelloid diatom species, Encyonopsis neerlandica sp. nov., is described from several moorland pools from The Netherlands. The new species belongs to the complex of species around E. microcephala. Based on light and detailed scanning electron microscopy, the morphology of Encyonopsis neerlandica is discussed and compared to similar species from this complex. Encyonopsis neerlandica is characterized by its rather large valve dimensions, the narrowly to clearly lanceolate valve outline with convex to weakly convex margins and rostrate to subcapitate apices. The distal raphe fissures are ventrally deflected. There is a clear difference between the rounded areolae near the valve margin and the transapically elongated areolae near the axial area.Notes on the ecology of the species are included.

Download Full-text

On the identity of the rare Fragilaria subconstricta (Fragilariaceae), with Fragilaria species forming ribbon-like colonies shortly reconsidered

Plant Ecology and Evolution ◽

10.5091/plecevo.2019.1619 ◽

2019 ◽

Vol 152 (2) ◽

pp. 327-339 ◽

Cited By ~ 4

Author(s):

David Heudre ◽

Carlos E. Wetzel ◽

Laura Moreau ◽

Bart Van de Vijver ◽

Luc Ector

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Rare Species ◽

Central Area ◽

Similar Species ◽

New Synonyms ◽

Freshwater Pond ◽

Large Numbers ◽

Northeastern France ◽

Scanning Electron

Background and aims – During phytoplankton surveys of a freshwater pond in Northeastern France, Fragilaria subconstricta (Bacillariophyceae) was observed. This rare diatom was present in large numbers in several plankton samples from Lachaussée Pond in the French Grand Est region. Methods – The morphology of Fragilaria subconstricta was examined in detail using light and scanning electron microscopy. Its identity is discussed and it is compared to the morphologically most similar species, especially Fragilaria capucina, F. mesolepta Rabenhorst, F. neointermedia and F. tenuistriata. Key results – Fragilaria subconstricta produces ribbon-like colonies and has narrow linear-lanceolate valves with slightly rostrate ends. The central area is rectangular, usually small or even absent. Spatulate linking spines are present all along the valve margins and a single rimoportula is located near one apex at the valve face-mantle junction. An amended diagnosis and new synonyms are proposed for this species. Additionally, the type material of Fragilaria mesolepta and a population of the very rare species Fragilaria capucina have been investigated and illustrated. Conclusions – Fragilaria subconstricta and F. tenuistriata are synonyms. Fragilaria capucina s. str. is a rare species in Europe, and the majority of records for this species should be considered part of the Fragilaria capucina “Sippenkomplex” sensu Krammer & Lange-Bertalot (1991).

Download Full-text

Gomphonema svalbardense sp. nov., a new freshwater diatom species (Bacillariophyta) from the Arctic Region

Phytotaxa ◽

10.11646/phytotaxa.170.4.2 ◽

2014 ◽

Vol 170 (4) ◽

pp. 250 ◽

Cited By ~ 3

Author(s):

Eveline Pinseel ◽

Katerina Kopalova ◽

Bart Van de Vijver

Keyword(s):

Central Area ◽

Arctic Region ◽

The Arctic ◽

Similar Species ◽

New Taxon ◽

Diatom Species ◽

Svalbard Archipelago ◽

Freshwater Diatoms ◽

Freshwater Diatom ◽

The Arctic Region

During a survey of freshwater diatoms from lakes in the region of Petuniabukta on Spitsbergen (Svalbard Archipelago) a new Gomphonema species, G. svalbardense sp. nov., has been recorded. The new taxon was previously cited in the literature as G. angustatum var. undulatum but this identification proved to be erroneous. Detailed morphology description of G. svalbardense based on light and scanning electron microscopy is presented in this paper and the morphological features of the taxon have been compared with similar species. Gomphonema svalbardense is characterized by its typical linear, almost naviculoid outline with undulating margins, with clearly inflated central part, asymmetric central area, lateral raphe with simple straight proximal endings and the weakly radiate striae. History, ecology and biogeography of the species, mainly based on literature data, have been included.

Download Full-text

Sellaphora labernardierei (Sellaphoraceae, Bacillariophyta), a new epilithic species from French spring and four new combinations within the genus Sellaphora

Phytotaxa ◽

10.11646/phytotaxa.260.3.3 ◽

2016 ◽

Vol 260 (3) ◽

pp. 235 ◽

Cited By ~ 8

Author(s):

AUDE BEAUGER ◽

CARLOS E. WETZEL ◽

OLIVIER VOLDOIRE ◽

ALEXANDRE GARREAU ◽

LUC ECTOR

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Central Area ◽

Mineral Waters ◽

New Combinations ◽

French Massif Central ◽

Small Species ◽

Massif Central ◽

Floristic Survey ◽

Scanning Electron

During a floristic survey of freshwater springs in the French Massif Central region, a new Sellaphora species (Bacillariophyceae) was found and is hereby described: Sellaphora labernardierei sp. nov. This new small species, with linear to linear-elliptical valves, slightly inflated in the middle, is formally described using light and scanning electron microscopy. The species has a single H-shaped chloroplast and striae usually biseriate tending to be uniseriate near the centre of the valve. The valve dimensions, the valve, pole and central area shapes, and the striae density and pattern allow their separation from similar taxa belonging to the genera Eolimna, Naviculadicta and Sellaphora. The ecological preferences of Sellaphora labernardierei are mineral waters with high nitrate concentrations. The examination of similar taxa belonging to the genera Eolimna and Naviculadicta and their characteristics lead to propose four new combinations of Sellaphora species.

Download Full-text

Four new species of monoraphid diatoms from Western Sichuan Plateau in China

Phytotaxa ◽

10.11646/phytotaxa.479.3.3 ◽

2021 ◽

Vol 479 (3) ◽

pp. 257-274

Author(s):

Q.M. YOU ◽

K. ZHAO ◽

Y.L. WANG ◽

P. YU ◽

J.P. KOCIOLEK ◽

...

Keyword(s):

Electron Microscopy ◽

New Species ◽

Central Area ◽

Morphological Characteristics ◽

Similar Species ◽

Small Species ◽

Western Sichuan ◽

The Relationship ◽

Scanning Electron ◽

Apical Axis

Four new monoraphid diatoms are examined and described from a high-altitude (> 3000 m) region of western Sichuan, China. The descriptions are based on light and scanning electron microscopy observations, and the four new species are compared with similar taxa worldwide. Achnanthidium sichuanense sp. nov. has small, lanceolate-elliptical valves, with rounded apices. The outline and central area differentiate it from similar species. The unique characteristic of Eucocconeis undulatum sp. nov. is that it has valves that are undulate along the apical axis, forming an “H”-shaped area on both raphe and rapheless valves as seen in light microscope (LM). Platessa mugecuonesis sp. nov. and Platessa lanceolata sp. nov. are two small species, whose valve outlines and central areas make them different from other species in this genus. A. sichuanense sp. nov. and E. undulatum sp. nov. are discussed in terms of the relationship between “Achnanthidium & Psammothidium” and “Eucocconeis & Psammothidium”, as these genera are difficult to separate according to morphological characteristics.

Download Full-text

A new species of Neidiomorpha (Bacillariophyceae) from Dianshan Lake in Shanghai, China

Phytotaxa ◽

10.11646/phytotaxa.423.2.6 ◽

2019 ◽

Vol 423 (2) ◽

pp. 99-104

Author(s):

FEN LUO ◽

QI YANG ◽

KAIJUAN GUO ◽

TENGTENG LIU ◽

QUANXI WANG ◽

...

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

New Species ◽

Central Area ◽

Diatom Species ◽

Dianshan Lake ◽

A New Species ◽

Scanning Electron

A new diatom species, Neidiomorpha dianshaniana sp. nov., found in Dianshan Lake in Shanghai, China, is described herein. The morphology of N. dianshaniana has been documented by light and scanning electron microscopy. Neidiomorpha dianshaniana valves are elliptical in outline with rostrate apices. Raphe is almost straight and filiform. The axial area is narrow and linear. The central area is small, round to transversely elliptical or irregular. Striae are slightly radiate and almost parallel near the apices. Puncta are arranged in undulating longitudinal rows. Neidiomorpha dianshaniana’s most visible feature is its lack of central constriction, in which respect it differs from the three other species in the genus Neidiomorpha.

Download Full-text

Distrionella coxiana, a new fragilarioid diatom species (Bacillariophyceae) from Tierra del Fuego, Patagonia, Argentina

Plant Ecology and Evolution ◽

10.5091/plecevo.2019.1587 ◽

2019 ◽

Vol 152 (2) ◽

pp. 385-391

Author(s):

Valeria Casa ◽

Gabriela Mataloni ◽

Bart Van de Vijver

Keyword(s):

Typical Feature ◽

Morphological Features ◽

Tierra Del Fuego ◽

New Taxon ◽

Diatom Species ◽

Unique Combination ◽

Diatom Flora ◽

Electron Microscopical ◽

Scanning Electron ◽

Freshwater Diatom

Background and aims – A few years ago, a new survey started of the freshwater diatom flora from peatbogs of Tierra del Fuego (southern Argentina). During this survey, an unknown fragilarioid diatom belonging to the genus Distrionella that could not be identified using the currently available literature was discovered. Methods – Using both Light Microscopical and Scanning Electron Microscopical techniques, the morphology of the unknown Distrionella species has been analysed. The new taxon is properly described, illustrated and compared with all other possible similar Distrionella taxa, known worldwide. Key results – Distrionella coxiana possesses a unique combination of morphological features that excludes conspecificity with all other members of the genus; it is characterized in having narrow, linear valves with small, capitate apices. Transapical ribs, a typical feature of the genus Distrionella, are only weakly developed. One rimoportula is observed close to the apices. Both apices have well-developed apical porefields. The girdle bands bear one complete row of poroids often accompanied by a second, incomplete row of small poroids. Notes on the occurrence and ecology of the new taxon are added.

Download Full-text