Size-dependent variations in phytoplankton and protozoan community structure across the St. Lawrence River transition region

The zhalong wetland water environment is an important part of the ecological environment, The protozoan community structure of Zhalong wetland was researched in this article. We can monitoring water pollution degree through the analysis of protozoan population, this research investigated protozoa population structure in qiqihar zhalong wetland through the PFU method and direct mining water in water samples, and analyse the physiological and biochemical parameters to assess the quality of water quality changes during May-October in 2012, the result show that 74 protozoa were observed including ciliate fleshiness shrimp center, flagellate less. In comparison with clean water inside, can use light and feed on algae native species number is more, different water quality in different conditions, protozoa composition has a very significant difference.

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Protozoan Community Structure in a Fractal Soil Environment

Protist ◽

10.1078/1434-4610-00060 ◽

2001 ◽

Vol 152 (3) ◽

pp. 203-218 ◽

Cited By ~ 26

Author(s):

B FINLAY

Keyword(s):

Community Structure ◽

Soil Environment ◽

Protozoan Community

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Impact of Protozoan Grazing on Bacterial Community Structure in Soil Microcosms

Applied and Environmental Microbiology ◽

10.1128/aem.68.12.6094-6105.2002 ◽

2002 ◽

Vol 68 (12) ◽

pp. 6094-6105 ◽

Cited By ~ 201

Author(s):

Regin Rønn ◽

Allison E. McCaig ◽

Bryan S. Griffiths ◽

James I. Prosser

Keyword(s):

Community Structure ◽

Bacterial Community ◽

Nutrient Solution ◽

Bacterial Communities ◽

Bacterial Community Structure ◽

Denaturing Gradient Gel Electrophoresis ◽

Rrna Gene ◽

Soil Microcosms ◽

Protozoan Grazing ◽

Protozoan Community

ABSTRACT The influence of grazing by a mixed assemblage of soil protozoa (seven flagellates and one amoeba) on bacterial community structure was studied in soil microcosms amended with a particulate resource (sterile wheat roots) or a soluble resource (a solution of various organic compounds). Sterilized soil was reinoculated with mixed soil bacteria (obtained by filtering and dilution) or with bacteria and protozoa. Denaturing gradient gel electrophoresis (DGGE) of PCR amplifications of 16S rRNA gene fragments, as well as community level physiological profiling (Biolog plates), suggested that the mixed protozoan community had significant effects on the bacterial community structure. Excising and sequencing of bands from the DGGE gels indicated that high-G+C gram-positive bacteria closely related to Arthrobacter spp. were favored by grazing, whereas the excised bands that decreased in intensity were related to gram-negative bacteria. The percentages of intensity found in bands related to high G+C gram positives increased from 4.5 and 12.6% in the ungrazed microcosms amended with roots and nutrient solution, respectively, to 19.3 and 32.9% in the grazed microcosms. Protozoa reduced the average bacterial cell size in microcosms amended with nutrient solution but not in the treatment amended with roots. Hence, size-selective feeding may explain some but not all of the changes in bacterial community structure. Five different protozoan isolates (Acanthamoeba sp., two species of Cercomonas, Thaumatomonas sp., and Spumella sp.) had different effects on the bacterial communities. This suggests that the composition of protozoan communities is important for the effect of protozoan grazing on bacterial communities.

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Microplankton community structure and the impact of microzooplankton grazing during an Emiliania huxleyi bloom, off the Devon coast

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315402005593 ◽

2002 ◽

Vol 82 (3) ◽

pp. 359-368 ◽

Cited By ~ 29

Author(s):

E.S. Fileman ◽

D.G. Cummings ◽

C.A. Llewellyn

Keyword(s):

Community Structure ◽

Phytoplankton Community ◽

Emiliania Huxleyi ◽

Pigment Analysis ◽

Protozoan Community ◽

Grazing Mortality ◽

Standing Stocks ◽

The Impact ◽

Microzooplankton Grazing ◽

High Reflectance

Phytoplankton and microzooplankton community structure and the impact of microzooplankton grazing were investigated during a one-day study of an Emiliania huxleyi bloom off the coast of Devon during July 1999. Vertical profiles were undertaken at four stations, along a transect which crossed from a low reflectance to a high reflectance area as seen by satellite imagery. Microzooplankton dilution grazing experiments, coupled with pigment analysis to determine class specific grazing rates, were performed at two of these stations.Highest concentrations of chlorophyll-a (5·3 mg m−3) and accessory pigments were measured inside the area of high reflectance. Phytoplankton standing stocks ranged between 1588 and 5460 mg C m−2 and were also highest in the area of high reflectance. The phytoplankton community was dominated by coccolithophores and diatoms in low reflectance waters and by photosynthetic dinoflagellates in high reflectance areas. Microzooplankton standing stocks ranged between 905 and 2498 mg C m−2. Protozoa dominated the microzooplankton community. The protozoan community comprised a relatively even mixture of heterotrophic dinoflagellates, non-choreotrich and choreotrich ciliates in low reflectance waters. However, non-choreotrich ciliates dominated the communities inside the high reflectance area. Of the heterotrophic ciliates, a predatory ciliate Askenasia sp. dominated both non-choreotrich abundance and biomass.Results from grazing experiments showed that 60–64% of the chlorophyll-a biomass was consumed daily by the microzooplankton. Highest grazing mortality was associated with peridinin (dinoflagellates) and alloxanthin (cryptophytes). Lower grazing rates were found on fucoxanthin (diatoms and prymnesiophytes). Our results indicate that grazing on E. huxleyi in the area of remotely sensed high reflectance was low and highest grazing was on photosynthetic dinoflagellates and cryptophytes.

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Variations in the community structure of biofilm-dwelling protozoa at different depths in coastal waters of the Yellow Sea, northern China

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315417001680 ◽

2017 ◽

Vol 99 (1) ◽

pp. 43-50 ◽

Cited By ~ 8

Author(s):

Mamun Abdullah Al ◽

Yangyang Gao ◽

Guangjian Xu ◽

Zheng Wang ◽

Henglong Xu ◽

...

Keyword(s):

Species Richness ◽

Community Structure ◽

Coastal Waters ◽

Yellow Sea ◽

Northern China ◽

Marine Ecosystems ◽

Artificial Substrates ◽

The Yellow Sea ◽

Individual Species ◽

Protozoan Community

Biofilm-dwelling protozoa are a primary component of microbiota and play important roles in the functioning of microbial food webs such as the mediation of carbon and energy flux from plankton to benthos in marine ecosystems. To demonstrate the vertical pattern of the protozoan communities, a 1-month baseline survey was carried out in coastal waters of the Yellow Sea, northern China. A total of 40 samples were collected using glass slides as artificial substrates at four depths: 1, 2, 3.5 and 5 m. A total of 50 species were identified, comprising seven dominant and eight commonly distributed species. Species richness and individual species abundances showed a clear decreasing trend down the water column from 1 to 5 m, although the former peaked at a depth of 2 m. Multivariate approaches revealed that protozoan community structure differed significantly among the four depths, except for those at 2 and 3.5 m. Maximum values of species richness, diversity and evenness generally decreased with depth although they peaked at either 2 or 3.5 m. These results suggest that water depth may significantly shape the community patterns of biofilm-dwelling protozoa in marine ecosystems.

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