Epiphyton of oligotrophic lakes of Leningrad region

2021 ◽  
pp. 71-79
Author(s):  
Elena V. Stanislavskaya
Keyword(s):  
Community Structure ◽  
Dominant Species ◽  
Taxonomic Composition ◽  
Species Level ◽  
Taxonomic Structure ◽  
Leningrad Region ◽  
Oligotrophic Lakes ◽  
Epiphytic Algae ◽  
Lake Ecosystems ◽  
Epiphytic Communities

Here are results of investigation of taxonomic composition, community structure and dominant species of epiphytic algae in 12 oligotrophic lakes located in different geomorphic regions of Leningrad region. In summer epiphytic communities there were 385 algal taxa, they belonged to 6 taxonomic divisions: Cyanophyta (Cyanoprokaryota) – 50 (13%), Bacillaryophyta – 175 (45%), Chlorophyta – 37 (10%), Charophyta – 118 (30%), Xanthophyta – 4 (1,55%), Rhodophyta – 1 (0,45%). The taxonomic structure of each lake was predominant diatoms and desmids, but the biomass was dominated by zygnems and green algae. In total, the taxonomic composition of the epiphyton in the studied lakes is similar, the differences are revealed at the species level. The structure of dominanting epiphyton complex was rather constant and composed by a small number of species. The greatest contribution to the epiphyton was made by Tabellaria flocculosa and species of the genus Bulbochaete. The structure of the epiphyton reflects the undisturbed nature of lake ecosystems, as well as their northern location.

scholarly journals Community structure of aquatic insects (Ephemeroptera, Plecoptera, and Trichoptera) in Cerrado streams of Paraguay, Paraná, and São Francisco river basins

2013 ◽  
Vol 13 (1) ◽  
pp. 97-107 ◽  
Author(s):  
Renato de Mei Romero ◽  
Mônica Ceneviva-Bastos ◽  
Gustavo Henrique Baviera ◽  
Lilian Casatti
Keyword(s):  
Community Structure ◽  
Aquatic Insects ◽  
Regional Differences ◽  
River Basins ◽  
Taxonomic Composition ◽  
Taxonomic Resolution ◽  
Sao Francisco River ◽  
Original Distribution ◽  
São Francisco River

We evaluated qualitatively and quantitatively the community structure of aquatic insects (Ephemeroptera, Plecoptera, and Trichoptera) in 19 streams in areas of Cerrado in the Paraguay, Paraná, and São Francisco river basins. The number of genera and taxonomic composition were compared at spatial (at the hydrographic basins level) and conservation levels (more preserved and less preserved areas). The influence of spatial and environmental factors in richness and abundance was also evaluated. The geographical distribution of Grumicha, Coryphorus, and Austrotinodes was expanded. The highest Trichoptera richness was found in the São Francisco river basin (F = 5,602, p = 0,004) and a higher number of Ephemeroptera genera occurred in the relatively less preserved sites (F = 6,835, p = 0,009). The pattern of genera distribution was different among basins (R = 0,0336, p = 0,001), but it was similar among relatively less and more preserved areas (R = -0,039, p = 0,737). These findings can be explained by the low impact level in these streams and also by the taxonomic resolution used in this study. Latitude and instream diversity were the most important factors to explain the variation in genera richness and abundance (p = 0.004 and p = 0.026, respectively). Hence, the regional differences can be attributed to spatial influences, quantity or quality of habitats and the original distribution of taxa within each basin.

scholarly journals Insights into the pan-microbiome: skin microbial communities of Chinese individuals differ from other racial groups

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Marcus H. Y. Leung ◽  
David Wilkins ◽  
Patrick K. H. Lee
Keyword(s):  
Community Structure ◽  
Species Level ◽  
Racial Groups ◽  
Opportunistic Pathogens ◽  
Single Population ◽  
Site Specific ◽  
Skin Site ◽  
Community Membership ◽  
Network Analyses ◽  
Host Properties

Abstract Many studies have characterized microbiomes of western individuals. However, studies involving non-westerners are scarce. This study characterizes the skin microbiomes of Chinese individuals. Skin-associated genera, including Propionibacterium, Corynebacterium, Staphylococcus and Enhydrobacter were prevalent. Extensive inter-individual microbiome variations were detected, with core genera present in all individuals constituting a minority of genera detected. Species-level analyses presented dominance of potential opportunistic pathogens in respective genera. Host properties including age, gender and household were associated with variations in community structure. For all sampled sites, skin microbiomes within an individual is more similar than that of different co-habiting individuals, which is in turn more similar than individuals living in different households. Network analyses highlighted general and skin-site specific relationships between genera. Comparison of microbiomes from different population groups revealed race-based clustering explained by community membership (Global R = 0.968) and structure (Global R = 0.589), contributing to enlargement of the skin pan-microbiome. This study provides the foundation for subsequent in-depth characterization and microbial interactive analyses on the skin and other parts of the human body in different racial groups and an appreciation that the human skin pan-microbiome can be much larger than that of a single population.

Diversity and community structure of Ephemeroptera in freshwater stream of Megamalai hills, Tamil Nadu, India

ENTOMON ◽  
2021 ◽  
Vol 46 (4) ◽  
pp. 279-284
Author(s):  
S. Barathy ◽  
T. Sivaruban ◽  
Srinivasan Pandiarajan ◽  
Isack Rajasekaran ◽  
M. Bernath Rosi
Keyword(s):  
Community Structure ◽  
Species Diversity ◽  
Air Temperature ◽  
Tamil Nadu ◽  
Dominant Species ◽  
Diversity Indices ◽  
Low Diversity ◽  
Freshwater Stream ◽  
Species Diversity Indices ◽  
High Diversity

In the study on the diversity and community structure of Ephemeroptera in the freshwater stream of Chinnasuruli falls on Megamalai hills, a total of 523 specimens belonging to thirteen genera and five families were collected in six month periods. Of the five families, Teloganodidae and Leptophlebiidae exhibited high diversity and Caenidae showed low diversity. Choroterpes alagarensis (Leptophlebiidae) is the most dominant species. Diversity indices such as Shannon and Simpson indices showed that diversity was maximum in November and December and it was minimum in August and January. Canonical Correspondence Analysis revealed that rainfall, water flow, turbidity, and air temperature were the major stressors in affecting the Ephemeropteran community structure.

scholarly journals Taxonomic composition and biodiversity of the gut microbiome from patients with irritable bowel syndrome, ulcerative colitis, and asthma

2022 ◽  
Vol 25 (8) ◽  
pp. 864-873
Author(s):  
A. Y. Tikunov ◽  
A. N. Shvalov ◽  
V. V. Morozov ◽  
I. V. Babkin ◽  
G. V. Seledtsova ◽  
...  
Keyword(s):  
Ulcerative Colitis ◽  
Irritable Bowel Syndrome ◽  
Gut Microbiota ◽  
Gut Microbiome ◽  
Taxonomic Composition ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Taxonomic Structure ◽  
Opportunistic Bacteria ◽  
Irritable Bowel

To date, the association of an imbalance of the intestinal microbiota with various human diseases, including both diseases of the gastrointestinal tract and disorders of the immune system, has been shown. However, despite the huge amount of accumulated data, many key questions still remain unanswered. Given limited data on the composition of the gut microbiota in patients with ulcerative colitis (UC) and irritable bowel syndrome (IBS) from different parts of Siberia, as well as the lack of data on the gut microbiota of patients with bronchial asthma (BA), the aim of the study was to assess the biodiversity of the gut microbiota of patients with IBS, UC and BA in comparison with those of healthy volunteers (HV). In this study, a comparative assessment of the biodiversity and taxonomic structure of gut microbiome was conducted based on the sequencing of 16S rRNA genes obtained from fecal samples of patients with IBS, UC, BA and volunteers. Sequences of the Firmicutes and Bacteroidetes types dominated in all samples studied. The third most common in all samples were sequences of the Proteobacteria type, which contains pathogenic and opportunistic bacteria. Sequences of the Actinobacteria type were, on average, the fourth most common. The results showed the presence of dysbiosis in the samples from patients compared to the sample from HVs. The ratio of Firmicutes/Bacteroidetes was lower in the IBS and UC samples than in HV and higher the BA samples. In the samples from patients with intestinal diseases (IBS and UC), an increase in the proportion of sequences of the Bacteroidetes type and a decrease in the proportion of sequences of the Clostridia class, as well as the Ruminococcaceae, but not Erysipelotrichaceae family, were found. The IBS, UC, and BA samples had signif icantly more Proteobacteria sequences, including Methylobacterium, Sphingomonas, Parasutterella, Halomonas, Vibrio, as well as Escherichia spp. and Shigella spp. In the gut microbiota of adults with BA, a decrease in the proportion of Roseburia, Lachnospira, Veillonella sequences was detected, but the share of Faecalibacterium and Lactobacillus sequences was the same as in healthy individuals. A signif icant increase in the proportion of Halomonas and Vibrio sequences in the gut microbiota in patients with BA has been described for the f irst time.

scholarly journals Characteristics of Benthos communities in Laoting area of Hebei Province

2020 ◽  
Vol 206 ◽  
pp. 02024
Author(s):  
Li Guanglou ◽  
Cao Hongmei ◽  
Ye wei
Keyword(s):  
Community Structure ◽  
Benthic Community ◽  
Dominant Species ◽  
Diversity Index ◽  
Hebei Province ◽  
Benthic Community Structure ◽  
Number Of Species ◽  
Evenness Index ◽  
Sea Area ◽  
Richness Index

According to a survey of benthos in the Laoting sea area of Hebei Province on May 24th 2019, a total of 40 benthos species were obtained, of which mollusks have the largest number, followed by annelids and arthropods. The dominant species are Sternaspis sculata and Ringicula doliaris. The number of species obtained in this survey is much lower than the historical average. The diversity index is significantly lower than that in the April 2008 survey, and the evenness index and richness index have declined slightly, indicating that the benthic community structure in this sea area tends to be simplistic, stability tends to deteriorate.

Shark longline fishery of Papua New Guinea: size and species composition and spatial variation of the catches

2020 ◽  
Vol 71 (6) ◽  
pp. 627
Author(s):  
William T. White ◽  
Leontine Baje ◽  
Sharon A. Appleyard ◽  
Andrew Chin ◽  
Jonathan J. Smart ◽  
...  
Keyword(s):  
Papua New Guinea ◽  
Dominant Species ◽  
New Guinea ◽  
Species Level ◽  
Longline Fishery ◽  
Specific Identification ◽  
Level Information ◽  
Sea Area ◽  
Number Of Individuals ◽  
Species Being

This study provides the first detailed investigation of the catches of the shark longline fishery in Papua New Guinea. Fisheries observers collected data on shark catches from a total of 318 longline sets between May and June 2014, before its closure in July 2014. In all, 14694 sharks were recorded with a total estimated biomass of 439 tonnes (Mg). Eighteen species of sharks were recorded in the observer data, with the most dominant species being Carcharhinus falciformis, which constituted more than 90% of the total catches by both weight and number of individuals. The level of observer misidentification was low (<10%), which reflected the use of region-specific identification guides by well-trained fisheries observers. The most diverse catches were in the Solomon Sea area, whereas catches in most other areas, particularly the Bismarck Sea areas, were less diverse and more strongly dominated by C. falciformis. Size and sex ratios varied by species, highlighting the importance of obtaining species-level information from the fishery being investigated. Any consideration by fisheries managers to reopen this fishery needs to consider the effect this will have on the species targeted and the livelihoods of coastal fishers who also rely on the same resources.

scholarly journals Fish assemblages in a tidal flat

2003 ◽  
Vol 46 (2) ◽  
pp. 233-242 ◽  
Author(s):  
Ana Lúcia Vendel ◽  
Sabine Granado Lopes ◽  
César Santos ◽  
Henry Louis Spach
Keyword(s):  
Cluster Analysis ◽  
Community Structure ◽  
Tidal Flat ◽  
Seasonal Changes ◽  
Dominant Species ◽  
Fish Assemblages ◽  
Seasonal Pattern ◽  
Abundant Species ◽  
Structure Index ◽  
Total Capture

Studies were carried out on fish assemblages in a tidal flat. Samples were obtained monthly at low tide of the half moon in the tidal flat of Paranaguá Bay, Brazil, with two seine nets, one with a 1 mm mesh, 30 m in length and 3 m in height and another with a 10 mm mesh, 65 m in length and 2 m in height. A total of 8,890 fish were captured, comprising 24 families and 53 species. The most abundant species were Harengula clupeola and Atherinella brasiliensis, which represented 63.4% of the total, capture. A seasonal tendency was observed in the abundance of fishes, with less fishes being captured during winter and part of spring. The number of species showed a seasonal pattern, with the gradual decrease through winter and a marked increase in summer. The community structure index indicated seasonal changes in the assemblage. The faunistic similarities between months separated the 12 months into four major groups. The seasonal pattern was apparent in the numerically dominant species and the Cluster Analysis revealed five main groups.

The impacts of deglaciation and human activity on the taxonomic structure of prokaryotic communities in Antarctic soils on King George Island

2018 ◽  
Vol 30 (5) ◽  
pp. 278-288 ◽  
Author(s):  
E.V. Pershina ◽  
E.A. Ivanova ◽  
E.V. Abakumov ◽  
E.E. Andronov
Keyword(s):  
Bacterial Species ◽  
Taxonomic Composition ◽  
South Shetland Islands ◽  
Soil Microbiome ◽  
Taxonomic Structure ◽  
Rrna Gene ◽  
King George Island ◽  
Antarctic Soils ◽  
Operational Taxonomic Units ◽  
Taxonomic Analysis

AbstractThe soil microbiome was investigated at environmentally distinct locations on King George Island in the South Shetland Islands (Antarctic Peninsula) using 16 S rRNA gene pyrosequencing. The taxonomic composition of the soil prokaryotes (bacteria and archaea) was evaluated at three sites representing human-disturbed soils (Bellingshausen Station) and soils undergoing different stages of deglaciation (fresh and old moraines located near Ecology Glacier). The taxonomic analysis revealed 20 bacterial and archaeal phyla, among which Proteobacteria (29.6%), Actinobacteria (25.3%), Bacteroidetes (15.8%), Cyanobacteria (11.2%), Acidobacteria (4.9%) and Verrucomicrobia (4.5%) comprised most of the microbiome. In a beta-diversity analysis, the samples formed separate clusters. The Bellingshausen Station samples were characterized by an increased amount ofNostocsp. andJanibactersp. Although the deglaciation history had less of an effect on the soil microbiome, the early stages of deglaciation (Sample 1) had a higher proportion of bacteria belonging to the families Xanthomonadaceae, Sphingomonadaceae and Nocardioidaceae, whereas the older moraines (Sample 2) were enriched with Chthoniobacteriacae and N1423WL. Solirubrobacteriales, Gaiellaceae and Chitinophagaceae bacteria were present in both stages of deglaciation, characterized by genus-level differences. Taxonomic analysis of the abundant operational taxonomic units (OTUs) revealed both endemic (Marisediminicola antarctica,Hymenobacter glaciei) and cosmopolitan bacterial species in the microbiomes.

scholarly journals Comparison of Community and Function of Dissimilatory Nitrate Reduction to Ammonium (DNRA) Bacteria in Chinese Shallow Lakes with Different Eutrophication Degrees

Water ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 174 ◽  
Author(s):  
Xiaowen Li ◽  
Chunlei Song ◽  
Zijun Zhou ◽  
Jian Xiao ◽  
Siyang Wang ◽  
...  
Keyword(s):  
Community Structure ◽  
Bacterial Community ◽  
Shallow Lakes ◽  
Nitrate Reduction ◽  
Bacterial Community Structure ◽  
Physical Parameters ◽  
Lake Chaohu ◽  
Lake Ecosystems ◽  
Dissimilatory Nitrate Reduction ◽  
Significant Difference

Dissimilatory nitrate reduction to ammonium (DNRA) plays an important role in controlling nitrogen (N) loading in lake ecosystems. However, studies on the linkage between DNRA bacterial community structure and lake eutrophication remain unclear. We examined the community and abundance of DNRA bacteria at six basins of four shallow lakes with different degrees of eutrophication in China. Measurements of the different forms of N and phosphorus (P) in the water column and interstitial water as well as total organic carbon (TOC) and sulfide in the sediments in summer (July 2016) were performed. The nutritional status of Lake Chaohu was more serious than that of the lakes in Wuhan, including Lake Qingling, Lake Houguan, and Lake Zhiyin by comparing geochemical and physical parameters. We found a higher abundance of the nrfA gene, which is a function gene of DNRA bacteria in sediments with higher contents of TOC and sulfide. Moreover, nitrate was a significant factor influencing the DNRA bacterial community structure. A significant difference of the DNRA bacterial community structure between Lake Chaohu and the lakes in Wuhan was discovered. Furthermore, DNRA bacterial abundance and community positively correlated with NH4+ and Chl a concentrations in Lake Chaohu, in which a percent abundance of dominant populations varied along eutrophication gradients. Overall, the abundance and community structure of the DNRA bacteria might be important regulators of eutrophication and cyanobacteria bloom in Lake Chaohu.

What, If Anything, Is a Nummulite Bank?

2018 ◽  
Vol 48 (4) ◽  
pp. 276-287 ◽  
Author(s):  
Cesare A. Papazzoni ◽  
Mona Seddighi
Keyword(s):  
Dominant Species ◽  
Recent Literature ◽  
Alternative Interpretation ◽  
Taxonomic Composition ◽  
Unexpected Result ◽  
Foraminiferal Assemblage ◽  
Percentage Composition ◽  
Extensive Survey ◽  
Robust Model ◽  
Original Definition

Abstract Since the introduction of the concept of a “nummulite bank” more than 50 years ago, the significance of these peculiar sedimentary structures has been debated, especially whether they are of autochthonous or allochthonous origin. At first considered as substantially autochthonous, an alternative interpretation as allochthonous deposits was suggested in the mid-1980s to explain the observation of sedimentary features indicating displacement of the nummulite tests. In more recent literature, we found examples of non-uniform use of the nummulite bank concept; sometimes the ‘banks’ are vaguely described as nummulite-rich beds, and illustrations may not allow recognition of the features characteristic of the real banks. In an attempt to achieve a scientifically robust model explaining the genesis of the nummulite banks, our objective was to test the original definition, based upon the most fundamental and useful characteristics that can be observed in the field, even in non-optimal outcrop conditions: the A/B ratio and the percentage composition (dominance) of the fossil assemblage. Both can be quantified using simple techniques on samples collected for this purpose. In an extensive survey of nummulite banks and non-banks from Italy, Spain, Romania, and Germany, we determined A/B ratios and taxonomic composition of the nummulite assemblages. Recognized nummulite banks are characterized by A/B ratios <60 and dominance of one species accounting for at least 75% of the specimens of Nummulites. Non-bank samples show A/B ratios between 60–350 and dominance usually <50%. An unexpected result was the discovery of an ‘Assilina bank’, characterizing both conditions for recognition of a nummulite bank, but with Assilina cuvillieri as the dominant species representing >75% of the larger foraminiferal assemblage.

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