Oricymba rhynchocephala sp. nov., a new cymbelloid diatom (Bacillariophyceae) from Xianju National Park in Zhejiang Province, China

Phytotaxa ◽  
2018 ◽  
Vol 340 (1) ◽  
pp. 63 ◽  
Author(s):  
WEI ZHANG ◽  
GUANG-XIA SHANG ◽  
J. PATRICK KOCIOLEK ◽  
LI-QING WANG ◽  
RUI-LEI ZHANG

During a survey of freshwater diatoms from Xuedong stream in the Xianju National Park, Zhejiang Province, China, a new cymbelloid species, Oricymba rhynchocephala sp. nov. has been recorded. This species is assigned to the genus Oricymba by virtue of having a ridge separating the valve face and mantle, the presence of apical pore fields, stigma with a single external opening but two internal openings, and areolae with dentate occlusions. A detailed morphological description of the new species, O. rhynchocephala, is presented, based on light and scanning electron microscopy. Oricymba rhynchocephala sp. nov. is characterized by having a linear-lanceolate outline with slightly arched valve margins towards rounded and clearly rostrate apices, as well as radiate striae. The taxon is morphologically compared with similar species of the genus Oricymba. The new species, can be easily separated from other species in Oricymba by its obvious rostrate apices. The report of this new species from Zhejiang Province adds to our understanding the morphology and distribution of the genus Oricymba in China.

Phytotaxa ◽  
2016 ◽  
Vol 272 (2) ◽  
pp. 134 ◽  
Author(s):  
WEI ZHANG ◽  
XIN QI ◽  
J. PATRICK KOCIOLEK ◽  
LI-QING WANG ◽  
RUI-LEI ZHANG

During a survey of freshwater diatoms from streams in the Xianju National Park, Zhejiang Province, China, a new cymbelloid species, Oricymba xianjuensis sp. nov. has been recorded. This species is assigned to the genus Oricymba by virtue of having a ridge separating the valve face and mantle, the presence of apical pore fields, and areolar openings with dentate occlusions. A detailed morphological description of the new species O. xianjuensis is presented, based on light and scanning electron microscopy. Oricymba xianjuensis sp. nov. is characterized by having a ridge along the valve face, as well as a linear-lanceolate outline with a moderately gibbous central portion gradually tapering towards the round, slightly protracted poles, a slightly lateral raphe with widened proximal endings and strongly deflected distal endings, and radiate striae. The taxon is morphologically compared with similar species of the genus Oricymba. The new species looks most similar to O. latirotundata, but is separated from this species by having more narrow, linear valves and a more tumid ventral margin. These findings add to our understanding the morphology and distribution of the genus Oricymba in China.


Phytotaxa ◽  
2015 ◽  
Vol 236 (3) ◽  
pp. 257 ◽  
Author(s):  
Wei Zhang ◽  
Yan Ling Li ◽  
J Patrick Kociolek ◽  
Rui Lei Zhang ◽  
Li Qing Wang

During a survey of freshwater diatoms from streams in the west region of the Tianmu Mountains, Zhejiang Province, China, a new Oricymba species, Oricymba tianmuensis sp. nov. has been recorded. A detailed morphology description of O. tianmuensis is presented, based on light and scanning electron microscopy. Oricymba tianmuensis sp. nov. is characterized by a ridge along the valve face typical of the genus, as well as a linear-lanceolate, symmetrical or slightly dorsiventral outline with a gibbous central portion gradually tapering or nearly paralleling towards the bluntly cuneate poles, a distinct rhombic-lanceolate asymmetric central area with a distinct stigma on the ventral side of the central nodule, a slightly lateral raphe with widened proximal endings and strongly deflected distal endings, and weakly radiate striae. Morphological features of the taxon are compared with similar species, and the biogeography of the genus is summarized.


Phytotaxa ◽  
2018 ◽  
Vol 375 (4) ◽  
pp. 274 ◽  
Author(s):  
WEI ZHANG ◽  
GUANGXIA SHANG ◽  
JHONE PATRICK KOCIOLEK ◽  
LIQING WANG ◽  
HONGXIN TAN

During a survey of freshwater diatoms from Shibadukeng stream in the Xianju County, Zhejiang Province, China, a new gomphonemoid species, Gomphonema bicepiformis sp. nov. has been recorded. The new species is diagnosed from all others in the genus based on morphology as observed with both light and scanning electron microscopy. Valves of Gomphonema bicepiformis are lanceolate with a gibbous central region. The headpole is broadly rounded, clearly capitate and the footpole is also broadly rounded, capitate. The axial area is wide, lanceolate-rhombic, broad at mid-valve, reaching 3/4 of the total breadth. There are circular to irregularly-shaped depressions in the axial area on the exterior of the valve surface often appearing as light spots in LM. The new species was compared with G. biceps, G. obstipum, G. manubrium, G. pyrenaicum, G. guayabense and G. nipponica, all of which resemble Gomphonema bicepiformis in outline, but differ from the new species in specific details of size, striae density, and extent of the axial area. This species occurs in relatively low conductivity and clean water in Zhejiang, China.


Phytotaxa ◽  
2019 ◽  
Vol 425 (1) ◽  
pp. 49-56
Author(s):  
YAN-LING LI ◽  
MING-YAN BAO ◽  
WEI LIU ◽  
JOHN PATRICK KOCIOLEK ◽  
WEI ZHANG

During a survey of freshwater diatoms from streams in the upper reaches of the Liujiang River, Guangxi Province, China, a new Cymbella species, Cymbella liujiangensis sp. nov. was recorded. A detailed morphological description of C. liujiangensis is presented, based on light and scanning electron microscopy. The main features of C. liujiangensis include strongly dorsiventral valves with slightly truncate and obtusely rounded ends and one very large, transaspically-elongated stigma positioned on the ventral side of the central nodule and adjacent to the middle ventral striae. The new species is compared with C. dorsenotata, C. aspera, C. peraspera, C. australica, C. praerupta, C. convexa, C. crassistigmata, C. graciliformis and C. simonsenii, all of which show similarities to Cymbella liujiangensis, but differ in details of size, valve shape, striae density, puncta density, and number of stigmata.


Phytotaxa ◽  
2021 ◽  
Vol 494 (2) ◽  
pp. 208-218
Author(s):  
DMITRY CHUDAEV ◽  
INGRID JÜTTNER ◽  
ZLATKO LEVKOV

This is the first detailed taxonomic study of the genus Navicula in the Krasnodar Territory of the Caucasus region, Russia. During the study of the genus in waterbodies of the Adegoy River valley 15 taxa were recorded. Two species, N. adegoyensis sp. nov. and N. pseudocryptofallax sp. nov., are described as new to science. Their morphology is studied by light and scanning electron microscopy, and comparisons with morphologically similar species are provided. The use of the name N. avenacea for N. lanceolata sensu auct. is discussed. Navicula diversity was higher in the Adegoy River than in pools elsewhere in the river valley.


Phytotaxa ◽  
2021 ◽  
Vol 508 (2) ◽  
Author(s):  
DMITRY CHUDAEV ◽  
INGRID JÜTTNER ◽  
BART VAN DE VIJVER

During a survey of the diatom flora of the Adegoy River (Krasnodar Territory, Russia), an unknown Fragilaria species (Bacillariophyta) was found that could not be identified using the currently available literature and here we describe it as a new species. The morphology of Fragilaria irregularis sp. nov. was studied using light and scanning electron microscopy and compared to similar species including Fragilaria deformis, F. rinoi, F. septentrionalis and Fragilariforma bicapitata. It differed from these taxa in several characters. Most observed valves showed an irregular striation pattern, a feature not observed in other species. Other important differences include valve outline (linear with parallel margins) and stria density (7–14 in 10 µm, lower compared to all other species). The new taxon has a linear valve outline with parallel to weakly convex margins, subcapitate apices and a very irregular, coarse striation pattern.


Phytotaxa ◽  
2014 ◽  
Vol 184 (4) ◽  
pp. 208 ◽  
Author(s):  
Priscila Izabel Tremarin ◽  
Thelma Ludwig ◽  
Lezilda Torgan

Examination of samples from different aquatic environments from Brazil revealed the presence of a new Aulacoseira species. Aulacoseira veraluciae Tremarin, Torgan & T. Ludwig is described and illustrated with light and scanning electron microscopy, and its morphology compared with that of similar species, such as A. muzzanensis (Meister) Krammer, A. granulata (Ehrenberg) Simonsen and A. agassizii (Ostenfeld) Simonsen. The new species is characterized mainly by the straight pervalvar rows of areolae, morphology of the linking spines, shape and position of the rimoportulae on the valve mantle, deepness and thickness of the ringleiste.


Phytotaxa ◽  
2017 ◽  
Vol 308 (2) ◽  
pp. 249 ◽  
Author(s):  
ZHONGYAN ZHANG ◽  
PATRICK RIOUAL ◽  
YUMEI PENG ◽  
XIAOPING YANG ◽  
ZHANGDONG JIN ◽  
...  

This paper describes a new Cymbella species from an alpine lake in the Pamir Mountains, NW China, with the aid of light and scanning electron microscopy and morphometric analyses. The morphology of the new species, named Cymbella pamirensis, is discussed and compared to similar species. The main morphometric features distinguishing Cymbella pamirensis from similar species of Cymbella are the outline and size of the valves. Cymbella pamirensis has been observed in surface sediment and core samples from Lake Sate Baile Dikuli, an alkaline, mesotrophic lake of the Pamir Mountains.


Phytotaxa ◽  
2014 ◽  
Vol 186 (2) ◽  
pp. 61 ◽  
Author(s):  
YUMEI PENG

A new medium-sized species of Hippodonta (Bacillariophyceae) is described from Lake Qinghai, China. The morphology and ultrastructure of Hippodonta qinghainensis sp. nov. are described using light and scanning electron microscopy. This new species is compared with similar species of Hippodonta using conventional and geometric morphometric analyses. Hippodonta qinghainensis can be separated from the other species of Hippodonta by a unique combination of characters that include an elliptic-lanceolate to rhombic-lanceolate valve shape, non protracted apices, the absence of fascia, relatively coarse, uniseriate striae and the presence of two rows of lineolae around the valves apices.


Phytotaxa ◽  
2019 ◽  
Vol 405 (3) ◽  
pp. 147
Author(s):  
P. YU ◽  
Q-M. YOU ◽  
W-T. PANG ◽  
Y. CAO ◽  
Q-X. WANG

Five new species are described in this study: Achnanthidium jiuzhaienis sp. nov., Achnanthidium epilithica sp. nov., Achnanthidium limosua sp. nov., Achnanthidium subtilissimum sp. nov., and Kolbesia sichuanenis sp. nov. Classification was based on light microscopy (LM) and scanning electron microscopy (SEM). A. jiuzhaienis sp. nov. belongs to the “A. pyrenaicum complex” of the genus Achnanthidium, this classification was based on certain characteristics, such as the possession of transpically-elongated areolae and deflected external distal raphe fissures. A. epilithica sp. nov., A. limosua sp. nov., and A. subtilissimum sp. nov. belong to the “A. minutissimum complex” of the genus Achnanthidium, this classification was based on certain characteristics, such as the possession of straight external distal raphe fissures and round or elliptical areolae. Kolbesia sichuanenis sp. nov. was found to belongs to the Kolbesia genus, based on its elongated areolae and striae comprised of one macroareola. All five species were sufficiently different from other similar species to be considered unique separate species based on their valve outline, shape of the axial and center areas, and density of striae of each taxon. These new species derived from the epilithic and epiphytic collections of four alkaline lakes in Jiuzhai Valley, Sichuan Province, Southwest China.


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