Am Stegskreuz 3b

Hofheim am Taunus, Germany

Am Stegskreuz 3b

Hofheim am Taunus, Germany
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Metzeltin D.,Am Stegskreuz 3b | Tremarin P.I.,Federal University of Paraná
Iheringia - Serie Botanica | Year: 2011

The study of periphytic material sampling in the Atlantic Rainforest of Southeast Brazil revealed the occurrence of a new species, Eunotia fuhrmannii sp. nov., found in humid rocks associated to Sphagnum L. The taxon has strongly dorsiventral valve with a median ridge, rounded to cuneate-obtuse apex, prominent polar nodules, spaced striae in the middle, and shortened at the junction of valve face with the mantle. E. fuhrmannii distinguished from similar species, as E. prolongata var. simplex Hustedt e E. brinkmannii Metzeltin & Lange-Bertalot, mainly by the shape of valve ends, density of striae, position of polar nodules and shape of terminal raphe fissures.

Cantonati M.,Museo delle Science MUSE | Metzeltin D.,Am Stegskreuz 3b | Soninkhishig N.,National University of Mongolia | Lange-Bertalot H.,Goethe University Frankfurt
Phytotaxa | Year: 2016

The stalked diatom Didymosphenia is being thoroughly studied because it can cause serious nuisance blooms. The species most commonly involved is D. geminata. Although Didymosphenia species occur in running waters and lakes, published reports generally refer to lotic habitats. Given the applied interest in Didymosphenia, as well as its suitability for fundamental ecological studies, here we report an observation of a Didymosphenia bloom occurring on the southern part of the eastern shore of the large oligotrophic Lake Hövsgöl (Mongolia). LM and SEM observations revealed that the bloom was formed by Didymosphenia laticollis. The bloom extended for a long stretch of the eastern shore whilst on the opposing lake margin no bloom was visible, where a different Didymosphenia species was collected (D. mongolica). We interpreted the Lake Hövsgöl D. laticollis bloom in light of the most updated knowledge on Didymosphenia blooms ecophysiology. Lake Hövsgöl meets all main environmental requirements for Didymosphenia bloom formation: conditions are oligotrophic and phosphorus is the limiting factor, waters are very transparent and benthic light availability is consequently high, alkalinity is relatively high, and stable rocky substrata in a hydrologically-turbulent environment are widespread. The light-brown color of the bloom is in good agreement with experimental results suggesting that low-SRP conditions promote bloom formation in the presence of high light and alkalinity, because energy is converted to stalk material (the primary site of alkaline phosphatase production in Didymosphenia) rather than in cells. We speculate that the occurrence of the bloom on the eastern shore and its absence on the western shore might depend upon morphology, land use, and climate change causing alkalinity and organic phosphate inputs on the eastern side. © 2016 Magnolia Press.

Li Y.,CAS Nanjing Institute of Geography and Limnology | Li Y.,Natural History Museum in London | Williams D.M.,Natural History Museum in London | Metzeltin D.,Am Stegskreuz 3b | And 2 more authors.
Journal of Phycology | Year: 2010

Tibetiella pulchra Y. L. Li, D. M. Williams et Metzeltin is described from River Nujiang. Its main features are heteropolar valves, which are linear with capitate ends; narrow sternum, expanding at its center; 2-5 rimoportulae at each apex; uniseriate striae; two short projections arising on the surface above each apical pore plate; and an ocellulimbus, extending from the edge of the valve margin to the edge of the valve surface. Of these characters, it is defined by the 2-5 rimoportulae at each apex. T. pulchra was common to abundant on rocks in the samples examined herein. © 2009 Phycological Society of America.

Hu Z.,CAS Nanjing Institute of Geography and Limnology | Hu Z.,University of Chinese Academy of Sciences | Li Y.,CAS Nanjing Institute of Geography and Limnology | Metzeltin D.,Am Stegskreuz 3b
Acta Botanica Croatica | Year: 2013

This paper describes three new Cymbella species from high altitude lakes of Hengduan Mountains region, southwest China. Cymbella heihainensis Li et Gong nov. spec. is similar to C. modicepunctata Krammer, C. asiatica Metzeltin, Lange-Bertalot et Li, Y., but differs from them in valve size, stigmata, raphe ending and also striae number. Cymbella shudunensis Li et Metzeltin nov. spec. is related to C. terrafuegiana, but differs in wider valve size, larger central area and coarser puncta. C. shudunensis differs from C. proxima Reimer in Patrick et Reimer group in reverse lateral raphes at the proximal endings, and distinguished from C.cistula (Ehrenberg) O. Kirchner group in the absent central area on dorsal side. Cymbella xingyunnensis Li and Gong sp. nov. resembles the group around C. proxima, and the most similar taxon is C. sinensis Metzeltn et Krammer, which can be distinguished by its lack of stigmata. © 2013 by Acta Botanica Croatica.

Li Y.,CAS Nanjing Institute of Geography and Limnology | Metzeltin D.,Am Stegskreuz 3b | Gong Z.,CAS Nanjing Institute of Geography and Limnology
Chinese Journal of Oceanology and Limnology | Year: 2010

We describe two new species of Sellaphora from Lake Fuxian, Yunnan Plateau, China. Based on both light and scanning electron microscopy, these species are described as S. yunnanensis sp. nov. and S. sinensis sp. nov. The primary features of S. yunnanensis are: elliptical to linear-elliptical valves with broadly rounded ends, straight filiform raphe, almost straight central endings and small, slightly expanding central pores, small central area, symmetrical or slightly asymmetrical central nodule. The primary features of S. sinensis are: elliptical valves, obtusely rounded ends, similar raphe and axial area, transapically less expanded central area, larger, elliptical central nodule. We compare these species to those of a similar shape and morphology. © 2010 Chinese Society for Oceanology and Limnology, Science Press and Springer Berlin Heidelberg.

Gong Z.,CAS Nanjing Institute of Geography and Limnology | Metzeltin D.,Am Stegskreuz 3b | Li Y.,CAS Nanjing Institute of Geography and Limnology | Edlund M.B.,St. Croix Research
Phytotaxa | Year: 2015

Three new freshwater diatoms are described from China’s Yunnan Plateau region in sediments from Lakes Fuxian, Erhai, and Lugu. Navicula craticuloides, nov. sp., N. gongii, nov. sp. and N. yunnanensis, nov. sp. were identified from light and scanning electron micrographs. The main features of N. craticuloides are its valve outline with rounded ends, a narrowlateral raphe, hooked terminal fissures, a linear axial area, a rectangular central area, and wavy striae towards the margins. The main features of N. gongii are narrowly lanceolate valves with long-protracted ends, a lateral raphe, a slightly curved axial area, and a rhombic or transversely expanded central area. The main features of N. yunnanensis are lanceolate valves with triundulate margins and cuneate ends and a lateral raphe. The new species have so far been found mainly in surficial sediment. ©2015 Magnolia Press

Gong Z.,CAS Nanjing Institute of Geography and Limnology | Li Y.,CAS Nanjing Institute of Geography and Limnology | Metzeltin D.,Am Stegskreuz 3b | Lange-Bertalot H.,Goethe University Frankfurt | Lange-Bertalot H.,Senckenberg Institute
Phytotaxa | Year: 2013

This paper describes five new Cymbella, one new Cymbopleura and one new Placoneis species from the late Pleistocene of the Jianghan Plain in China, based on light-and scanning electron microscopy of valve morphology. The characteristic morphological features of the seven new species differ from known established taxa by valve shape, both the central portion and apices, length/breadth ratio, shape of the central area and presence or absence of stigmata. All six cymbelloid taxa are as yet found only in fossil deposits of the Jianghan Plain. The Placoneis species, however is apparently conspecific with an extant population observed in Northern Myanmar (Burma, Southeast Asia). © 2013 Magnolia Press.

Li Y.,CAS Nanjing Institute of Geography and Limnology | Kociolek J.P.,University of Colorado at Boulder | Metzeltin D.,Am Stegskreuz 3b
Diatom Research | Year: 2010

This paper describes two new Gomphonema species from the southern Sichuan Province, China, and shows their valve morphology using light and scanning electron microscopy. The two species, Gomphonema sichuanensis sp. nov. and G. heilongtanensis sp. nov., were found in Lake Dashuicao and Lake Heilongtan. Main features of G. sichuanensis are clavate valves, broadly rounded headpole, narrowly rounded footpole, narrow axial area, indistinct central area, undulate and distinctly lateral raphe, clearly separated stigma from stria, and slightly radiate striae. Main features of G. heilongtanesis are clavate valves with wedge-shaped, acutely rounded headpole and narrowly rounded footpole, narrow axial area, small rounded central area, and parallel striae in the valve center becoming slightly radiate towards the apices. Despite a long history of research on freshwater diatoms in China, there is still much work to do to document the flora of this large and geographically complex country.

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