Desmid Flora Research Articles

Desmids of Brahmaputra valley, a major southern Asian river basin

Inadequate information on the diversity and dispersion of desmids has led to incomplete floristic data in the northeastern region of India. The present study focuses on contributing to the information on the diversity and geographical distribution of desmid in water bodies of the Brahmaputra River basin of the Indian subcontinent. During the period 2019–2022, desmid flora of 91 waterbodies were studied. Two-hundred-and-thirty-one taxa belonging to five families and 25 genera were recorded, out of which 94 were new records for the northeastern India. Desmidiaceae was the dominant family with 195 species and with 69 species Cosmarium was the dominant genus.

Desmids of Gorce Mts. Geobotanical studies

The presented work is the first comprehensive study on the desmids of mountainous areas of the Gorce region in Poland. The Gorce Mts flora of the order Desmidiales comprises 20 genera and 247 species. The most diverse genera in the Gorce Mts are Cosmarium with 99 taxa, Closterium with 39 taxa, Staurastrum with 38 taxa and Euastrum with 17 taxa. All reported taxa are described and documented by original hand drawings and microphotographs. Environmental data with geographical coordinates are included for all studied sites. Among the recorded taxa, eight (Actinotaenium borgeanum, Actinotaenium gelidum, Actinotaenium perminutum, Cosmarium alpestre, Cosmarium dispersum, Cosmarium paragranatoides, Closterium sublaterale, Staurastrum pyramidatum) are new for the Polish flora. An important factor affecting the biodiversity of desmids in the Gorce area is human activity. In typically anthropogenic habitats, which in the study area include roads and paths, 157 species were found (63.7% of the Gorce desmid flora). Many montane species, such as Closterium pusillum and Cosmarium decedens, associated with wet moss on rocks, had secondary habitats there. A group of 21 species found only in anthropogenic habitats can be considered anthropophytes of the studied area. There are also semi-natural habitats in the form of meadows that persist only due to human activity. The situation is similar to that of vascular plants. Clearings used until the 1980s showed significantly higher species richness than clearings where grazing has been abandoned for a long time. Overall, human activity has contributed to an increase of desmid species diversity in the Gorce region.

Periphytic algal flora of the low Doce river, Espírito Santo State, Brazil, after ore tailings flow, 2: ornamented cell-wall Cosmarium (Zygnematophyceae, Desmidiaceae)

ABSTRACT Present study aimed at carrying out the taxonomic survey of the ornamented cell-wall Cosmaria from the low Doce river region, Espírito Santo State. Material studied was collected between months October 2018 and February 2020. Thirty-three taxa were identified, from which 32 are new additions to the Espírito Santo State desmid flora, five are new records for Brazil (C. blyttii cf. var. basiornatum, C. cf. dentiferum, C. monomazum var. polymazum, C. sphagnicola var. pachygonum, and C. subcostatum var. subcostatum), and one for South America (C. isthmochondrum cf. var. biseriatum). Present study increased the knowledge on the genus Cosmarium in Espírito Santo State by adding both taxonomic and ecological information.

Kaçkar Dağları Milli Park’ından (Rize/Türkiye) yeni desmid kayıtları

The periphytic algal samples were taken from 14 lakes and one pond in the Kaçkar Mountains National Park in 2020. The samples were observed under light microscope for their morphometric characteristics based identification. At the end of the research, 78 taxa belonging to the Charophyta division were identified. 7 of them, which are Closterium jenneri var. curvatissimum (West & G.S.West) A.J.Brook & D.B.Williamson, Cosmarium margaritiferum f. regularis (Nordstedt) West & G.S.West, Euastrum ansatum var. concavum Willi Krieger, E. verrucosum var. coarctatum Delponte, E. verrucosum var. planctonicum West & G.S.West, Staurastrum capitulum Brébisson and S. sexcostatum Brébisson ex Ralfs, were determined as new records for the desmid flora of Turkey. In this paper, morphotaxonomy, ecology, and distribution of each species are discussed in detail and it has been also recorded the geographic distribution of desmid species in Turkey.

Taxonomic notes on genera Bourrellyodesmus and Xanthidium (Zygnematophyceae) from Chapada Diamantina, Bahia, Brazil

Here, we report some interesting periphytic desmids, collected in the Chapada Diamantina region, Caatinga domain, northeastern Brazil. Overall, seven taxa were identified, including two species (Bourrellyodesmus comperei, Xanthidium verrucosum) and one variety (Xanthidium concinnum var. longispinum), which are taxonomic novelties, in addition to other taxa of the desmid flora of Brazil. Taxonomic notes and ecological information were provided for each taxon.

Taxonomy and distribution of desmids in Karapuzha Dam, Western Ghats, Kerala

AbstractDuring the studies of algae in the Wayanad district, a notable diversity of desmids observed in the Karapuzha dam, Kerala, India. Karapuzha Dam is 700 to 2061 metres above sea level and is a part of Western Ghats. Thirty‐nine taxa of desmids were identified from Karapuzha Dam of Wayanad district from June 2019 to May 2020. The collection comprises ten genera of 39 desmids, including 24 species of Cosmarium, 5 Staurastrum, 2 Closterium, 2 Euastrum, 1 Gonatozygon, 1 Triplastrum, 1 Penium, 1 Spondylosium, 1 Micrasterias and 1 Arthrodesmus. Among these, Cosmarium regnesi var. montanum is new to India, 8 taxa are new to Kerala and 2 taxa are new to South India. Some rare and high altitude distributed species are found in the study. This desmid diversity relates to the oligotrophic nature of the dam. This paper is a pioneer attempt to document the desmid flora of Karapuzha Dam, Kerala.

How hidden is the diversity of the genus Cosmarium (Desmidiaceae) in the Brazilian Caatinga?

The Caatinga domain is the largest and most diverse tropical semiarid ecoregion of South America; however, little is known about the diversity of desmids it harbors, especially the genus Cosmarium (Desmidiaceae, Zygnematophyceae). Our study contributes to the knowledge of Cosmarium in the Caatinga through the report of 42 interesting taxa, including a new species (Cosmarium imperiale), 22 new records for South America, and 19 additions to the desmid flora from Brazil. The samples were gathered from periphytic material from the “Pantanal dos Marimbus” in the Chapada Diamantina region of Northeast Brazil. We provide taxonomic notes, ecological information, including habitat conditions with limnological data, and updated global distributions for all taxa of Cosmarium. A complementary quantitative study was performed during the last year of sampling (2018), which revealed that most taxa have their highest densities in the months with low precipitation and when the water's conductivity and transparency are greater. Our results also have implications for the conservation of the biota from Marimbus do Baiano and understand South America's desmids' biogeography since some rare taxa identified here were previously only known from other continents such as Europe and Africa.

Addition to the desmid flora (Charophyta: Desmidiales) of Nizhnevartovsk district, KMAO-Yugra, Russia

Five species of desmid algae new to Nizhnevartovsk city are reported. Three species (Closterium abruptum,Cl. jenneri, Euastrum ansatum) are rare for Nizhnevartovsk administrative region, one (Penium margaritaceum) is newfor Khanty-Mansi Autonomous Okrug – Yugra.

New or otherwise interesting desmid taxa from the Bangweulu region (Zambia). 3. Genus Cosmarium (Desmidiales)

Background and aims In a third contribution to the desmid flora of the Bangweulu wetlands in Zambia a selection of species from the genus Cosmarium is discussed for their taxonomy and geographical di

The effect of acetolysis on desmids

ABSTRACTAcetolysis, an oxidising technique common in palynological preparation, is beneficial for pollen analysts who employ it to remove ‘unwanted’ organic matter from peat and lake samples. Since this technique was introduced by G. Erdtman in 1934, however, several researches have noted concerns, such as the destruction of thin-walled pollen grains in addition to non-sporopollenin pollen components, and selective destruction of protoperidinioid dinoflagellate cysts. Desmids are conjugate green algae with a wide range of environmental preferences whose half-cells are known from sediments dating back to at least the Neogene (possibly as far back as the Devonian), and they have proven useful in modern and palaeolimnological studies (e.g. as indicators of nutrient loading, anthropogenic impact and drought). Desmids are rarely mentioned in palynological studies, however, except to illustrate fluvial transport to nearshore marine settings. A diverse desmid flora was found in samples processed without acetolysis from Smith's Bay in Lake Simcoe, and desmid and thecamoebian (testate amoeba) assemblage changes record eutrophication up-core. Very low concentrations of both desmids and Pediastrum, another group of algal non-pollen palynomorphs (NPP), record siltation and inhibition of photosynthesis attributed to two phases of land-clearing and agriculture (Wendat/Huron and Euro-Canadian). After acetolysis, the desmid abundance in the same residues drops significantly (between 36 and 100%, mean = 87%) and the assemblage is skewed towards the most robust Cosmarium spp. However, other low-relief NPP, like Pediastrum, may be easier to observe after acetolysis as they are not obscured by amorphous organic matter. Because of the observed detrimental impact acetolysis has on the desmid assemblage, recommendations include: (i) not acetolysing, as pollen and Pediastrum can be observed either way, or (ii) using a two-pronged approach where susceptible microfossils are observed pre-acetolysis and resistant ones observed post-acetolysis.

New or otherwise interesting desmid taxa from the Bangweulu region (Zambia). 2. Genera Staurodesmus, Staurastrum and Xanthidium (Desmidiales)

Background and aims – In a second contribution to the desmid flora of the Bangweulu wetlands in Zambia a selection of species from the genera Xanthidium, Staurodesmus and Staurastrum is discussed for their taxonomy and geographical distribution.Material and methods – Samples were collected from Lake Bangweulu and adjacent swamps as well as from Lake WakaWaka. Collection was by squeezing submerged plant material or using a plankton net.Key results – Four taxa are described as new to science: Staurodesmus bangweuluensis, Std. coutei, Std. thomassonii and Staurastrum onychophorum. Three taxa are recombined: Staurastrum zahlbruckneri var. africanum to S. bidentulum var. africanum, Staurastrum unicorne to Staurodesmus unicornis and Arthrodesmus curvatus to Staurodesmus curvatus. Xanthidium decoratum var. longispinum is raised to species level whereas two taxa, Staurodesmus subunguiferus var. longiradiatus and Std. longiradiatus var. granulatus were provided with new names: Staurastrum zambiense and S. zambiense var. granulatum, respectively.Conclusions – Almost all taxa discussed may be considered African endemics underlining the specific character of the African desmid flora. Many identifications in older desmid literature from Africa, especially infraspecific taxa assigned to species originally described from Europe, appear to need a critical revision.

Desmid flora of Chulband Dam, Gondia district, Maharashtra, (India).

Desmid flora of Chulband Dam, Gondia district, Maharashtra, (India).

Genus Cosmarium Corda from Thrissur Kole lands, Kerala

<p>The present investigation deals with sixty eight taxa of <em>Cosmarium</em> Corda collected from the Kole lands of Thrissur, Kerala. The Kole lands constitute part of Vembanad-Kol, which is declared as one of the Ramsar sites of Kerala. All the taxa are systematically described with illustrations and their distribution in India. Of these, six taxa are first time reported from India and twenty nine taxa are new additions to the algal flora of Kerala. <em>C. geminatum </em>Lund. var. <em>ornatum </em>Behre, <em>C. </em><em>indentatum</em> Gronbl. var. <em>ellipticum</em> Scott & Gronbl., <em>C. </em><em>pseudoconnatum</em> Nordst. var. <em>constictum </em>West, <em>C. </em><em>quadrifarium</em> Lund., <em>C. </em><em>quadriverrucosum</em> West & West var. <em>undulatum </em>Scott & Prescott and <em>C. </em><em>subturgidum</em> (Turn.) Schmidle are the new additions to the desmid flora of India.</p>

A contribution to the desmid flora of Southeastern Maine1

Abstract Eight peat bogs and wetlands near Steuben, ME were sampled in July 2005 to assess local diversity of freshwater algae. A surprising number of conjugating green algae, especially from the order Desmidiales, was seen even in this small local sample, summing up to 130 species and subspecific taxa. We present an overview of past floristic literature pertaining to desmid species distribution in New England and enrich the current checklist by 65 new records for the state of Maine. Additionally, eight taxa could not be confidently matched to known species, suggesting they may represent heretofore undescribed taxonomic entities. This, coupled with the fact that desmids can serve as water quality indicators, suggests that the desmid diversity in northern New England merits further attention and research.

Pesticide Influence on the Desmid Flora of a Reservoir in an Agricultural Region at Campo Verde, Mato Grosso, Brazil

The objective of the research was to investigate the influence of pesticides on the desmid flora. Five series of samples were taken between July 5, 2005, and April 6, 2006, for analysis of pesticide content and algal community structure in the Sao Lourenco River springs on the Pirassununga Ranch, Campo Verde, Mato Grosso. The greatest amounts of pesticides were detected in July, when the abundance of algae was also greatest. Positive correlations were determined between the concentrations of endosulfan (r = 0.94; p = 0.051), cyhalothrin (r = 0.96; p = 0.037) and endrin (r = 0.96; p = 0.037) and the biomass of desmids. Insecticides, such as endosulfan, inhibit the activity of ATPase, contributing considerably to the mortality of the biota, since ATP is of fundamental importance in the energy metabolism of all organisms. This suggests that the pesticides promote algal growth both by removing the small herbivores that feed on the algae and increasing the release of inorganic nutrients from decomposing animals in the water. Algae were least abundance in January, possibly due to the presence of the herbicide atrazine (r = -0.63; p > 0.05).

Desmids of the transitional bogs of the Middle Mazowsze Lowland

The author presents the results of the studies of several years on the desmid flora of nine transitional bogs located in the environs of Warsaw. 226 taxa were found belonging to 20 gen era. Moreover, 16 taxa of the <em>Mesotaeniaceae</em> family, representing 4 genera were identified. A few taxonomic corrections were made in relation to several taxa. The rank within the species was changed or it was transferred to another genus. Certain species and distinguished infraspecific taxa were criticized.

New records of Cosmarium Corda ex Ralfs (Desmidiaceae, Zygnematophyceae) in a tributary of the Itaipu Reservoir, Paraná, Brazil

This work is part of a survey of the desmid flora in a tributary of the Itaipu Reservoir, in the state of Parana, Brazil. The objective was to expand the knowledge base regarding the genus Cosmarium (Desmidiaceae, Zygnematophyceae). We conducted a qualitative analysis of 60 samples of phytoplankton, which were collected from along the banks of the Sao Francisco Falso River between July of 2003 and June of 2004. We identified, drew, and described 18 taxa of Cosmarium. Of those 18 taxa, 8 represent new records for the state of Parana: C. angulosum Breb. var. angulosum, C. bireme Nordst. var. bireme, C. clepsydra Nordst. var. clepsydra, C. cf. galeritum Nordst. var. borgei, C. ginzbergeri, C. norimbergense Reinsch var. norimbergense, C. protractum (Nageli) De Bary var. protractum, and C. rectangulare var. hexagonum (Elfving) G.S. West & West.

Desmid flora from four peat bogs in Serbia

The main objective of this paper is to report the desmid taxa identified from four Serbian peat bogs: Pester, Daic Lake on Mt. Golija, Crvene pode on Mt. Tara and Horgos. Samples were collected in the period from 2007 to 2011. In total, 220 desmid taxa from 22 genera were identified. The most species-rich genera are Cosmarium (81), Staurastrum (38) and Closterium (31). Of the total number, 66 desmid taxa are new for the Serbian desmid flora.

Desmid flora of mires in Central and Northern Moravia (Czech Republic)

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Desmids from Lake Nabugabo (Uganda) and adjacent peat bogs.

In 2006 the desmid flora of Lake Nabugabo and some adjacent peat bogs was studied. All in total some 108 taxa were identified. Fourteen taxa, most of them being only known from the African continent, are discussed in detail. Six taxa are newly described: Euastrum gemmatum var. quadrituberosum, Micrasterias stuhlmannii var. nabugabonum, Cosmarium nabugabonum, Xanthidium thomassonii, Staurodesmus eckertii var. africanus and Staurastrum capitulum var. foersteri. The morphological variation found in Staurastrum longicolle is discussed in the light of possible speciation of desmids in a limnetic environment.