scholarly journals Seasonal niche differentiation between evolutionary closely related marine bacteria

2020 ◽  
Author(s):  
Adrià Auladell ◽  
Albert Barberán ◽  
Ramiro Logares ◽  
Esther Garcés ◽  
Josep M. Gasol ◽  
...  
Keyword(s):  
Marine Bacteria ◽  
Niche Partitioning ◽  
Environmental Parameters ◽  
Niche Overlap ◽  
Niche Differentiation ◽  
Habitat Filtering ◽  
Coastal Marine ◽  
Class Level ◽  
Nucleotide Divergence ◽  
Selection Of

AbstractBacteria are highly dynamic in marine environments, where they play key biogeochemical roles. Here, we tested how similar the niche of closely related marine bacteria is and what are the environmental parameters modulating their ecological responses in a coastal oligotrophic time series. We further explored how conserved the niche is at broader taxonomic levels. We found that, for certain genera, niche similarity decreases as nucleotide divergence increases between closely related amplicon sequence variants, a pattern compatible with selection of similar taxa through habitat filtering. Additionally, we observed evidence of niche partitioning within various genera shown by the distinct seasonal patterns of closely related taxa. At broader levels, we did not observe coherent seasonal trends at the class level, with the order and family ranks conditioned to the patterns that exist at the genus level. This study explores the coexistence of niche overlap and niche partitioning in a coastal marine environment.

scholarly journals Seasonal niche differentiation among closely related marine bacteria

2021 ◽  
Author(s):  
Adrià Auladell ◽  
Albert Barberán ◽  
Ramiro Logares ◽  
Esther Garcés ◽  
Josep M. Gasol ◽  
...  
Keyword(s):  
Marine Bacteria ◽  
Environmental Filtering ◽  
Environmental Parameters ◽  
Niche Differentiation ◽  
Seasonal Abundance ◽  
Rrna Gene ◽  
Coastal Marine ◽  
Class Level ◽  
Nucleotide Divergence ◽  
Recurrent Patterns

AbstractBacteria display dynamic abundance fluctuations over time in marine environments, where they play key biogeochemical roles. Here, we characterized the seasonal dynamics of marine bacteria in a coastal oligotrophic time series station, tested how similar the temporal niche of closely related taxa is, and what are the environmental parameters modulating their seasonal abundance patterns. We further explored how conserved the niche is at higher taxonomic levels. The community presented recurrent patterns of seasonality for 297 out of 6825 amplicon sequence variants (ASVs), which constituted almost half of the total relative abundance (47%). For certain genera, niche similarity decreased as nucleotide divergence in the 16S rRNA gene increased, a pattern compatible with the selection of similar taxa through environmental filtering. Additionally, we observed evidence of seasonal differentiation within various genera as seen by the distinct seasonal patterns of closely related taxa. At broader taxonomic levels, coherent seasonal trends did not exist at the class level, while the order and family ranks depended on the patterns that existed at the genus level. This study identifies the coexistence of closely related taxa for some bacterial groups and seasonal differentiation for others in a coastal marine environment subjected to a strong seasonality.

scholarly journals Collection of Environmental Variables and Bacterial Community Compositions in Marian Cove, Antarctica, during Summer 2018

Data ◽  
2021 ◽  
Vol 6 (3) ◽  
pp. 27
Author(s):  
Hyo-Ryeon Kim ◽  
Jae-Hyun Lim ◽  
Ju-Hyoung Kim ◽  
Il-Nam Kim
Keyword(s):  
Bacterial Community ◽  
Community Composition ◽  
Marine Bacteria ◽  
Environmental Variables ◽  
Environmental Changes ◽  
Bacterial Community Composition ◽  
Composition Data ◽  
Decomposition Of Organic Matter ◽  
Class Level ◽  
Earth’S Climate

Marine bacteria, which are known as key drivers for marine biogeochemical cycles and Earth’s climate system, are mainly responsible for the decomposition of organic matter and production of climate-relevant gases (i.e., CO₂, N₂O, and CH₄). However, research is still required to fully understand the correlation between environmental variables and bacteria community composition. Marine bacteria living in the Marian Cove, where the inflow of freshwater has been rapidly increasing due to substantial glacial retreat, must be undergoing significant environmental changes. During the summer of 2018, we conducted a hydrographic survey to collect environmental variables and bacterial community composition data at three different layers (i.e., the seawater surface, middle, and bottom layers) from 15 stations. Of all the bacterial data, 17 different phylum level bacteria and 21 different class level bacteria were found and Proteobacteria occupy 50.3% at phylum level following Bacteroidetes. Gammaproteobacteria and Alphaproteobacteria, which belong to Proteobacteria, are the highest proportion at the class level. Gammaproteobacteria showed the highest relative abundance in all three seawater layers. The collection of environmental variables and bacterial composition data contributes to improving our understanding of the significant relationships between marine Antarctic regions and marine bacteria that lives in the Antarctic.

scholarly journals Foraging niche partitioning in sympatric seabird populations

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Christina Petalas ◽  
Thomas Lazarus ◽  
Raphael A. Lavoie ◽  
Kyle H. Elliott ◽  
Mélanie F. Guigueno
Keyword(s):  
Interspecific Competition ◽  
Niche Partitioning ◽  
Niche Differentiation ◽  
Sympatric Species ◽  
Foraging Strategies ◽  
Gps Tracking ◽  
Seabird Species ◽  
Foraging Range ◽  
Common Murre ◽  
Prey Items

AbstractSympatric species must sufficiently differentiate aspects of their ecological niche to alleviate complete interspecific competition and stably coexist within the same area. Seabirds provide a unique opportunity to understand patterns of niche segregation among coexisting species because they form large multi-species colonies of breeding aggregations with seemingly overlapping diets and foraging areas. Recent biologging tools have revealed that colonial seabirds can differentiate components of their foraging strategies. Specifically, small, diving birds with high wing-loading may have small foraging radii compared with larger or non-diving birds. In the Gulf of St-Lawrence in Canada, we investigated whether and how niche differentiation occurs in four incubating seabird species breeding sympatrically using GPS-tracking and direct field observations of prey items carried by adults to chicks: the Atlantic puffin (Fratercula arctica), razorbill (Alca torda), common murre (Uria aalge), and black-legged kittiwake (Rissa tridactyla). Although there was overlap at foraging hotspots, all species differentiated in either diet (prey species, size and number) or foraging range. Whereas puffins and razorbills consumed multiple smaller prey items that were readily available closer to the colony, murres selected larger more diverse prey that were accessible due to their deeper diving capability. Kittiwakes compensated for their surface foraging by having a large foraging range, including foraging largely at a specific distant hotspot. These foraging habitat specialisations may alleviate high interspecific competition allowing for their coexistence, providing insight on multispecies colonial living.

scholarly journals Niche partitioning by photosynthetic plankton as a driver of CO2-fixation across the oligotrophic South Pacific Subtropical Ocean

2021 ◽  
Author(s):  
Julia Duerschlag ◽  
Wiebke Mohr ◽  
Timothy G. Ferdelman ◽  
Julie LaRoche ◽  
Dhwani Desai ◽  
...  
Keyword(s):  
Mixed Layer ◽  
Niche Partitioning ◽  
Euphotic Zone ◽  
South Pacific ◽  
Niche Differentiation ◽  
Surface Mixed Layer ◽  
The South ◽  
The Core ◽  
Photosynthetic Eukaryotes ◽  
Phytoplankton Communities

AbstractOligotrophic ocean gyre ecosystems may be expanding due to rising global temperatures [1–5]. Models predicting carbon flow through these changing ecosystems require accurate descriptions of phytoplankton communities and their metabolic activities [6]. We therefore measured distributions and activities of cyanobacteria and small photosynthetic eukaryotes throughout the euphotic zone on a zonal transect through the South Pacific Ocean, focusing on the ultraoligotrophic waters of the South Pacific Gyre (SPG). Bulk rates of CO2 fixation were low (0.1 µmol C l−1 d−1) but pervasive throughout both the surface mixed-layer (upper 150 m), as well as the deep chlorophyll a maximum of the core SPG. Chloroplast 16S rRNA metabarcoding, and single-cell 13CO2 uptake experiments demonstrated niche differentiation among the small eukaryotes and picocyanobacteria. Prochlorococcus abundances, activity, and growth were more closely associated with the rims of the gyre. Small, fast-growing, photosynthetic eukaryotes, likely related to the Pelagophyceae, characterized the deep chlorophyll a maximum. In contrast, a slower growing population of photosynthetic eukaryotes, likely comprised of Dictyochophyceae and Chrysophyceae, dominated the mixed layer that contributed 65–88% of the areal CO2 fixation within the core SPG. Small photosynthetic eukaryotes may thus play an underappreciated role in CO2 fixation in the surface mixed-layer waters of ultraoligotrophic ecosystems.

scholarly journals Microbial dark carbon fixation fueled by nitrate enrichment

2021 ◽  
Author(s):  
Joseph H. Vineis ◽  
Ashley N. Bulseco ◽  
Jennifer L. Bowen
Keyword(s):  
Microbial Communities ◽  
Marine Sediments ◽  
Salt Marshes ◽  
Carbon Fixation ◽  
Niche Partitioning ◽  
Coastal Marine Sediments ◽  
Functional Relationships ◽  
Coastal Marine ◽  
Dark Carbon Fixation ◽  
The Impact

Anthropogenic nitrate amendment to coastal marine sediments can increase rates of heterotrophic mineralization and autotrophic dark carbon fixation (DCF). DCF may be favored in sediments where organic matter is biologically unavailable, leading to a microbial community supported by chemoautotrophy. Niche partitioning among DCF communities and adaptations for nitrate metabolism in coastal marine sediments remain poorly characterized, especially within salt marshes. We used genome-resolved metagenomics, phylogenetics, and comparative genomics to characterize the potential niche space, phylogenetic relationships, and adaptations important to microbial communities within nitrate enriched sediment. We found that nitrate enrichment of sediment from discrete depths between 0-25 cm supported both heterotrophs and chemoautotrophs that use sulfur oxidizing denitrification to drive the Calvin-Benson-Bassham (CBB) or reductive TCA (rTCA) DCF pathways. Phylogenetic reconstruction indicated that the nitrate enriched community represented a small fraction of the phylogenetic diversity contained in coastal marine environmental genomes, while pangenomics revealed close evolutionary and functional relationships with DCF microbes in other oligotrophic environments. These results indicate that DCF can support coastal marine microbial communities and should be carefully considered when estimating the impact of nitrate on carbon cycling in these critical habitats.

scholarly journals Temporal Variation in the Niche Partitioning of Lake Michigan Salmonines as it Relates to Alewife Abundance and Size Structure.

2021 ◽  
Author(s):  
Benjamin A. Turschak ◽  
Charles R. Bronte ◽  
Sergiusz J. Czesny ◽  
Brandon S. Gerig ◽  
Austin Happel ◽  
...  
Keyword(s):  
Ecological Niche ◽  
Lake Michigan ◽  
Nitrogen Isotopes ◽  
Size Structure ◽  
Prey Availability ◽  
Habitat Preferences ◽  
Niche Partitioning ◽  
Niche Overlap ◽  
Isotopic Niche ◽  
Resource Gradient

Stable isotope analyses offer a useful means for quantifying ecological niche dimensions, though few studies have examined isotopic response of an ecological community with respect to resource gradients such as fluctuations in prey availability. Stable carbon and nitrogen isotopes were measured for Lake Michigan salmonines and their prey collected from 2014 to 2016. Bayesian ellipse and mixing model analyses were used to quantify isotopic niche characteristics and diets, respectively, among species and years. During the three-year study period, abundance and size structure of preferred alewife prey changed substantially and offered an opportunity to explore predator isotopic niche response and diet shifts along a prey resource gradient. Results suggested increased reliance on alewives, especially small alewives, over the study period and were consistent with greater availability of this prey. However, differential use of alewife size classes and alternative prey sources by salmonine predators was apparent, which suggested possible resource partitioning. Characterization of ecological niche overlap using stable isotopes likely requires consideration of shared resource availability as well as specific prey and habitat preferences.

scholarly journals Low temporal variation in the intact polar lipid composition of North Sea coastal marine water reveals limited chemotaxonomic value

2012 ◽  
Vol 9 (3) ◽  
pp. 1073-1084 ◽  
Author(s):  
J. Brandsma ◽  
E. C. Hopmans ◽  
C. J. M. Philippart ◽  
M. J. W. Veldhuis ◽  
S. Schouten ◽  
...  
Keyword(s):  
North Sea ◽  
Microbial Community Composition ◽  
Principal Component ◽  
Environmental Parameters ◽  
Temporal Variations ◽  
Marine Water ◽  
Nutrient Concentrations ◽  
Multiple Sources ◽  
Coastal Marine ◽  
Algal Groups

Abstract. Temporal variations in the abundance and composition of intact polar lipids (IPLs) in North Sea coastal marine water were assessed over a one-year seasonal cycle, and compared with environmental parameters and the microbial community composition. Sulfoquinovosyldiacylglycerol (SQDG) was the most abundant IPL class, followed by phosphatidylcholine (PC), phosphatidylglycerol (PG) and diacylglyceryl-(N,N,N)-trimethylhomoserine (DGTS) in roughly equal concentrations, and smaller amounts of phosphatidylethanolamine (PE). Although the total concentrations of these IPL classes varied substantially throughout the year, the composition of the IPL pool remained remarkably constant. Statistical analysis yielded negative correlations between IPL concentrations and dissolved inorganic nutrient concentrations, but no changes in the overall planktonic IPL composition due to nutrient limitation were observed. Significant correlations between SQDG, PC, PG and DGTS concentrations and chlorophyll a concentrations and algal abundances indicated that eukaryotic primary producers, in particular Phaeocystis globosa, were the predominant source of IPLs at this site. However, while IPL concentrations in the water were closely tied to total algal abundances, the rapid succession of different algal groups blooming throughout the year resulted in only minor shifts in the IPL composition. Principal component analysis showed that the IPLs were derived from multiple sources, and that no IPL species could be exclusively assigned to a particular algal taxa or (cyano)bacteria. Thus, the most commonly occurring IPLs appear to have limited chemotaxonomic potential, highlighting the need to use targeted assays of more specific biomarker IPLs.

Identification of trophic niches of subterranean diving beetles in a calcrete aquifer by DNA and stable isotope analyses

2014 ◽  
Vol 65 (2) ◽  
pp. 95 ◽  
Author(s):  
Tessa M. Bradford ◽  
William F. Humphreys ◽  
Andrew D. Austin ◽  
Steven J. B. Cooper
Keyword(s):  
Stable Isotope ◽  
Trophic Ecology ◽  
Niche Partitioning ◽  
Niche Differentiation ◽  
Trophic Niche ◽  
Coi Gene ◽  
Stable Isotope Analyses ◽  
Prey Preferences ◽  
Diving Beetles ◽  
Isotope Analyses

The Yilgarn calcrete aquifers in Western Australia are an interesting system for investigating the process of speciation within subterranean habitats, because of the limited opportunities for dispersal between isolated calcretes. The presence of different-sized diving beetles (Dytiscidae) in separate calcretes, including sympatric sister-species pairs, suggests that species may have evolved within calcretes by an adaptive shift as a result of ecological-niche differentiation. We have studied the potential for trophic niche partitioning in a sister triplet of diving beetles, of distinctly different sizes, from a single aquifer. Fragments of the mitochondrial COI gene, specific to known species of amphipods and copepods, were polymerase chain reaction-amplified from each of the three beetle species, indicating that there is an overlap in their prey items. Significant differences were found in the detected diets of the three species, and results showed a propensity for prey preferences of amphipods by the large beetles and one species of copepod for the small beetles. A terrestrial source of carbon to the calcrete was suggested by stable isotope analyses. The combined approach of molecular, stable isotope and behavioural studies have provided insight into the trophic ecology of this difficult-to-access environment, providing a framework for more fine-scale analyses of the diet of different-sized species to examine speciation underground.

Climatic niche modeling reveals divergence between cytotypes in Eutrema edwardsii (Brassicaceae)

Botany ◽  
2018 ◽  
Vol 96 (12) ◽  
pp. 813-823
Author(s):  
Jared E. Mastin ◽  
Peter Anthamatten ◽  
Leo P. Bruederle
Keyword(s):  
Flow Cytometry ◽  
Genetic Material ◽  
Null Distribution ◽  
Niche Overlap ◽  
Niche Differentiation ◽  
Niche Modeling ◽  
The Arctic ◽  
The Novel ◽  
Principle Components Analysis ◽  
Components Analysis

Polyploidy among plants is most frequent in the arctic, where glaciation cycles put selective pressures on populations by repeated fragmentation and fluctuation in climate. Polyploids should have been more fit in the novel habitats created as glaciers receded because of increased genetic material and novel gene products, which results in phenotypic plasticity and rapid adaptation. Higher ploidy is then expected to confer a broader tolerance of environmental conditions. Eutrema edwardsii R. Br. (Brassicaceae) is an arctic-alpine mustard with a near circumpolar distribution that occurs as a tetraploid, hexaploid, and octaploid. We used flow cytometry to document the distribution of polyploid cytotypes using herbarium tissue, and modeled the niche of each cytotype to test for niche differentiation. Flow cytometry revealed four cytotypes among 85 individuals. Notably, 60% of the herbarium tissue assays were successful using tissue up to 50 years old. Principle components analysis was performed on 20 climatic variables, of which, the first four axes were used as environmental variables for niche modeling. Niche models were created for tetraploid and hexaploid populations and used to calculate niche overlap (Shoener’s D). Overlap between tetraploid and hexaploid models (D = 0.534) is lower than the null distribution (D = 0.681–0.944) supporting the hypothesis of niche divergence.

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