Science topic

Phytoplankton - Science topic

Free-floating minute organisms that are photosynthetic. The term is non-taxonomic and refers to a lifestyle (energy utilization and motility), rather than a particular type of organism. Most, but not all, are unicellular algae. Important groups include DIATOMS; DINOFLAGELLATES; CYANOBACTERIA; CHLOROPHYTA; HAPTOPHYTA; CRYPTOMONADS; and silicoflagellates.
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I'm doing stable isotope analysis to construct a reservoir food web. For that, I need to collect zooplankton and phytoplankton separately. The use of different mesh sizes solved the problem to some extent but can't obtain pure samples. Are there any methods other than that?
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After segregating through separate mesh sized nets, staining methods can distinguish between both types of phytoplankton
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I have to sampling phytoplankton and zooplankton for stable isotope analysis to construct reservoir food web.
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If you want to know what phytoplankton is in your system don’t use a net all. Phytoplankton can be as small as 1 μm.
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I found a published photo where author writes that this is diatom species Hyalosira delicatula. But I have some doubts about such conclusion.
Unfortunatedly I do not have any photographs and the description of Hyalosira delicaula. So, can anyone familiar with the genus Hyalosira confirm or refute this conclusion?
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Roksana, thank you.
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I want to learn as a species.
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I agree that Synedra is a likely ID but you may also want to consider Pinnularia. They are both pennate diatoms with a raphe and similar morphology. There are some slight differences in the shape particularly in the terminal morphology. When you encounter this taxa again carefully read the descriptions to tease out which genus you in fact have. A very good guide book to use is
Identifying Marine Phytoplankton Editor: Carmelo Tomas https://doi.org/10.1016/B978-0-12-693018-4.X5000-9
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The pigment is extracted from phytoplankton by the Zapata method.
At some point, chlorophyll a was not found in the sample.
However, when chlorophyll a is measured with 10-au, chlorophyll a is detected.
The strange thing is that it is extracted with standard.
Have you ever had a similar experience?
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Solved the problem! Acetone was the problem.
When I changed acetone to another company's product, chlorophyll was extracted again.
Perhaps there was a problem with the acetone produced at this time.
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I would like to see algal class abundance from my pigment (data one year). I need a great help from experts regarding how to start the CHEMTAX program since I have lack of knowledge in statistics.
Thanks
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Hi Mar,
The core part of CHEMTAX is basically to solve an overdetermined linear inverse problem. If you are an R player, the package `limSolve` by Karline Soetaert et al. provides an example of how you can do it. Try `help(limSolve::Chemtax)` in your console once you install it. Or find it in this link: https://search.r-project.org/CRAN/refmans/limSolve/html/Chemtax.html
Hope this helps. Good luck and regards,
Shun
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Hi all,
I want to test whether the primary production by phytoplankton from a whole year (so every day a measurement) predicted by model calculations differs from the field measurements of the primary production. Therefore, it wouldn't make sense to take the mean of the two years, but I want to test if the primary production on day 28 in the model differs from the measurement on that day and than I want to test that for al the days and in this way thest whether the model significantly differs from the measurements. What test should I use for this? or do I have to take multiple staps?
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When doing as Michel suggested, there may be weather abnormalities that correspond to differences observed and predicted.
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There is some information found related to this.
" the net productivity and growth rate of the phytoplankton are usually underestimated when bottled methods measuring dissolved oxygen are used in estimating phytoplankton respiration Steelmann-Nielsen (1975)".
So I need to know what is the solution to avoid this underestimation and what are other methods available instead of bottle methods?
Please share your valuable comments.
Thanks in advance.
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Interesting & valuable question! we are waiting for the experts.
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Hi Friend and colleague,
Anybody is working in field of algae can respond to me. I had query about Pamer index. 1969 and Shannon index .
Which index is better for studying water pollution in relation to algae
Because some of research article showed use of
Staub et. al. (1970) : shannon diversity is based on diversity index D
3.0 - 4.5 : Slight pollution
2.0 - 3.0 : Light pollution
1.0 - 2.0 : Moderate pollution
0.0 - 1.0 : Heavy pollution
Wilhm and Dorris (1968) proposed the following relationship between diversity index (D) and pollution status. D Condition
> 3 Clean water
1 - 3 Moderately polluted
< 1 Heavily polluted
Trivedi (1980 and 1981) on correlation of diversity index (D) and the degree of pollution as follows : Condition
> 4.0 : Clean water
3.0 - 4.0 : Very light pollution
2.0 - 3.0 : Moderate pollution
< 2.0 : Heavy pollution
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Shannon Weiner indicates the degree of better/stressful environment.
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Plamer index methodolgy
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Thanks you, Zahidul Islam :
As you said, If i had two spp., i.e., Oscillatoria 4, Chlorella 3 etc.
Thus, My Index values 4 + 3 = 7
Does is indicate Lack of pollution as per above index table
( Index values between 0-10 = Lack of organic pollution)
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Hi,
I'm trying to identify the alga I marked in the photo. Can you help? Thanks for your help.
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review genus Zygnema
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I have separate algal and zooplankton samples that I want to have stable isotope analysis of C and N performed on.
The samples were filtered onto 0.4 µm glass fibre filters (GF/F) that were then freeze-dried and stored at - 80 degrees. In error, the glass fibre filters were not pre-combusted or pre-weighed prior to having the zooplankton and algal samples filtered onto them.
Is there a way to still use these samples for stable isotope analysis of C and N? I have read that you can scape the material of the filter paper and then place in a tin foil boat for analysis but don't feel confident in the reliability of this approach.
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Hi !
If you get satisfactory results after checking the blank filters, you can use the scraping method for d15N. Just scrape off the layer of filter paper from behind without disturbing the top layer (avoid any contamination while doing so). For d13C, use a part of filter paper if the content is too high after acid fumigation.
Hope this helps !
Prachi
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Hello, everybody. My PhD research is about eutrophication
processes in a hypersaline lagoon which has registered episodes
of fish mortality. My study includes a phytoplankton species
inventory. I would like a guide of toxic and/or potential harmful
phytoplankton. Thanks to all.
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Thank you Mohamed Ben-Haddad . :)
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What is the best way to separate phytoplankton and zooplankton?
Sorting of freshwater plankton.
Thank you for your suggestions!
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It might look easy to just sieve your samples as many suggested, but in the end, it is advantageous to identify the species. E.g. so many of the protists are mixotrophs, i.e. fall in both categories (phyto- and zooplankton). Why do you need this distinction anyway? Maybe for writing it up, it might be easier to stick to the size fractions, instead of using the terms phyto- and zooplankton.
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question is related to identification of phytoplankton.
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Gonzalo Martín Thank u so much sir.
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it is related to identification of phytoplankton
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Shyam Kishore and Maria Van Herk Thank you so much .
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Can I include the Generalized Linear Model in Phytoplankton Community Structure studies? Please share some related reference papers if someone found the same. Thank you in Advance. Stay Safe and Stay Happy dear Researchers.
Kind Regards
Anila P Ajayan
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Let's start with a general linear model. This is a class of models that include simple linear regression, multiple linear regression, one-way anova, two-way anova, ancova, an so on. These models assume that the data are conditionally normal in distribution. Generalized linear models extend this to different types of observed data. For example, if you have a dichotomous outcome you might use logistic regression. If you have a count outcome variable, you might use Poisson regression. The Wikipedia article may be helpful: https://en.wikipedia.org/wiki/Generalized_linear_model#General_linear_models
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I have the value of Delta N for 3 producers (water column phytoplankton, sedimented attached microalgae, periphyton), primary consumers (zooplankton), tertiary consumers (different fish species).
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It is well described in the book by Brian Fry 'Stable Iostope Ecology'. Also very useful when it comes to calculation of mixing-models.
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I'm looking to describe an algal community, so I need a method that can work to preserve both diatoms and other algae. I've been looking at glutaraldehyde, but I'm not sure if that is the best option. Any help is appreciated!
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Hi Willow;
Phytoplankton are fixed with a Lugol-glycerol solution (2-3 % glycerol). Glycerol is required for flagellates. Please look at European Committee for Standardization, 2015. According to the standard method (European Committee for Standardization 2006), phytoplankton enumerations were carried out under an inverted microscope (Olympus CKX41) at magnifications of 400 and 600X. For each sample, at least 350 settling units of the dominant species were counted. Phytoplankton biovolume was calculated by multiplying the cell density and mean biovolume of the taxon, which was taken approximating geometric shapes of the least 25 individuals (Sun and Liu 2003).
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I was wondering if ecosystem metabolism (GPP-ER=NEP) could be measured using BOD bottles that are not completely filled with water (dark-light bottle method). In such a case, which problems could come from this approach?
Do you have a reference that could be useful to discern which method to use?
Thank you!
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I have delta N for Snail, 3 source organisms (organic matter from phytoplankton; benthic microalgae and peryphyton); primary consumers (zooplankton) and tertiary consumer is Hilsa fish of different sizes.
May I apply TP= [(deltaN primary consumers -deltaN primary producers)/3.4]+1 ( Post DM (2002) Using stable isotopes to estimate trophic position: Models, methods, and assumptions. Ecology 83:703–718)
If so, how can I calculate trophic transfer from primary producers to zooplankton, fish?
Should I use the average delN value of zooplankton as the primary consumer and the average delN value of each primary producers?
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2. You can consider a one-isotope mixing model and take into account trophic enrichment factors to estimate trophic contribution from producers to consumers.
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hello all scholars I need to know please the interpretation of CANOCO V 4.5 to analysis phytoplankton relation with environment, zooplankton and macrophyte coverage. please could you help me?
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Hi Demtew Etisa,
To relate hydrographical parameters and biological parameters, the RDA or CCA results can represent in Triplot. In the ordination diagram, relationship between environmental and biological variables were determined by considering length and directions of orientations and its angle between the variables. The arrows representing species which are pointing in the same direction of environmental variables or towards stations shows high positive correlation whereas, the opposite oriented arrows indicates high negative correlations. Similarly, the shorter the angle between the variables, greater the correlation and larger the angle, lesser the correlation. For better understanding , you can check the attached pdf.
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The levels of trace metals Co, Cu, Ni and Zn in both
dissolved and particulate phases of water from six branches
of Shatt Al-Arab River have been investigated during two
seasons, spring and summer 2006 by means of Atomic
Absorption Spectrophotometry. Levels recorded in μg/ml
were: Co (0.019-0.078), Cu(0.163 - 0.240), Ni(0.035 – 0.094)
and Zn (0.130–0.215) in dissolved phase during both seasons
compared to particulate phase in which levels recorded in
μg/g were Co (11.10 – 26.468), Cu(76.340- 376.543), Ni
(7.778 – 150.676) and Zn (222.546 – 654.128). These levels
were higher than most previous studies at the same sites. It is
appeared that all studied branches are highly polluted and
water appears highly turbid, viscose and greenish in color
due to the expected abundance of phytoplanktons.
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Thanks @John machell
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I am working on the dynamics in the phytoplankton assemblage of Lake Victoria. I need some guidance on the best approach to model the chlorophyll-a, and or phytoplankton diversity in the lake,
Are there any experts in the field (phytoplankton or modelling) to guide me during my research activities?
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Renan Ribeiro , Hello ,
how to add a porous plate in the flow (tidal current flow), to simulate the effect of the turbine (energy extraction) in the tidal current flow, in delft3d?
Thanks
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Guys, I took this picture and found this "circle" interesting, I need someone who can form me whatever it may be? If you have any questions, download a zoom image to check, as there is only this record. Do you think this circle could be of the genus Chlorella?
Best regards,
Ranielton de Moraes
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The photo is not ideal. I agree there is detritus, but among the detritus may be some strings of Pseudo-nitzschia spp. This is a Harmful Algal Bloom species.
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We plan to sample a lot of lakes one by one during several days, so we need something quick and reliable to characterize phytoplankton community.
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Long wish I could afford a fluoroprobe. I use the haemocytometer and differential interference contrast on the microscope. Thinking about whether I can use my vis-spectrometer (not UV, sadly) To do quick throughput of samples. Any thoughts?
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The specimen originates from lake water in Sweden.
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Desmidiales - Euastrum sp
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Can NIR drone/satellite systems determine which taxonomic groups of phytoplankton are present in surface waters, or can it only be used to quantify chlorophyll and other pigments?
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Sentinel 3 data for better analysis
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I have been exploring data in the Agean sea from MODIS product normalized fluorescence line-height (nFLH).
In many control areas, I have noticed a strange pattern on the fluorescence line-height values. Does anyone know if this is due to a problem in the sensor?
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I am not specifically familiar with MODIS or this type study. My experience with fluorescence determination and analytical work using fluorescent dye tracing, which is dated. There was an apparent abrupt change, that suggests to me an equipment shift, method or calculation shift. I don’t know specifically what is meant by line height, but am familiar enough to know that sometimes the graphical responses can change with equipment, so the running of fluorescent concentration standards before and after each sample, should take care of many or most differences as equipment or detectors age. And perhaps there has been a shift in phytoplankton function, that is causing the normalized values to be depressed, and at times below zero, so one would need to look into why there were no values below zero until the erratic response. If you are running standards, you might check if the line heights of the standards have been drifting or shifting. Sensors, light sources in fluorometer or other equipment shifts might also be considered.
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Hiya - As a zooplankton person this is quite simple using length to weight relationships. But I'm trying to figure out the approximate carbon weight of a phytoplankton that is for example 20 um. Are there length-weight relationships for phyotplankton too? Is it possible in the absence of chlorophyll-a and species data?
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Yes, people frequently use measured dimensions along one or two axes and simplified geometric shapes to estimate biovolume, see e.g. this one:
Hillebrand H, Dürselen C-D, Kirschtel D, Pollingher U, Zohary T (1999) Biovolume Calculation for Pelagic and Benthic Microalgae 1. J Phycol 35:403–424
...and then to convert from biovolume to biomass use for example:
Menden-Deuer S, Lessard EJ (2000) Carbon to volume relationships for dinoflagellates, diatoms, and other protist plankton. Limnol Oceanogr 45:569–579
hope this helps
-Leni
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Why Amphora genus of phytoplankton become dominant in slightely saline lake ?
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Many species in Amphora sensu lato are marine but an increasing number of species are being described from inland habitats. However, in spite of recent revisions of Amphora s.l. that included the elevation to the generic status of the subgenus Halamphora (Levkov 2009), the genera Amphora and Halamphora still appear to be insufficiently known in freshwater habitats.
The salinity barrier dividing the freshwater from the marine realm was supposed to be virtually impassable but Alverson et al. (2007)
showed that this did not apply to the thalassiosiroid diatoms.
More recently, Ruck et al. (2016),
working on the Surirellales and Rhopalodiales, proposed an interesting ‘stepping-stone’ hypothesis, based on comparative molecular-phylogeny evidence supporting the idea that the ancestrally-marine diatoms belonging to these groups would have used brackish waters as an intermediate habitat to which to adapt before invading freshwater environments. In the light of these papers, the most recent study by Stepanek & Kociolek (2019)
suggests that inland saline habitats are of particular interest for such studies: for diatom groups, such as Amphora and Halamphora, that have representatives
colonizing smaller inland waterbodies with elevated conductivity, these waterbodies might represent potential intermediate habitats from which the colonization of surrounding freshwaters could have taken place.
It thus makes sense from an evolutionary point of view that an Amphora s.l. species can become dominant in a slightly saline lake. However, as suggested by my Colleagues in previous replays, much more information on the taxon involved and on the environmental conditions would be needed to provide more ecological interpretation of your observation.
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I have flow cytometric data from a series of phytoplankton samples. I organized all the FCS files into flowSets using the flowCore package. My next step would be to determine compositional differences between the samples. The flowCore package offers some options for basic operations on the data, such as gating, subsetting, etc, but now I wonder if there are any more sophicticated packages for a more in-depth analysis. Any suggestions or experience shared would be highly appreciated!
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i highly recommend CytoExploreR
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Please, I need the identification key of the marine phytoplankton?
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Dear Prof. Carlos Pereira
Well received, thank you so much.
Kind Regards
Fatima
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We are interested to calculate biomass from cyanobacteria biovolume: has anyone applicable suggestions and formulas for that? I will appreciate any info, paper, formulas etc.!
Thank you!
Iasmina
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Follow
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CTAB or Phenol chloroform, which is better? Please guide me in detail
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Hi Rahul,
I tried with Qiagen DNeasy Plant mini Kit with modification, u can use filter paper method or plankton from net for extraction, but freeze throwing at Liquid nitrogen, and homogenization using bead beating is essential and after that incubation at 3-6hr at 55C
please refer: Nowinski et al.,2019(Nature -Scientific data)
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At what point (concentration) is sulphate lethal to phytoplankton?
Any relationship between sulphate concentration and algal growth and development?
How can one contruct an experiment to determine the effect of sulphate concentration on phytoplankton?
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Hi guys, I need your help identifying this phytoplankton?
I took this sample in fresh water on the São Francisco River
the family i believe is merismopediaceae
within the genre I believe it's Coelosphaerium
follow the link of a similar image, but the mucilage is different from the sample I have
Sincerely
Ranielton Moraes
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for M. wesenbergii the cels are too small, if it is not a Coelosphaerium, perhaps it is an Aphanocapsa.
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Using a Horiba FluoroMax - just getting going on this procedure for the first time and can't find any explicitly clear literature online.
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Fatty acids composition of microalgae differed from species to species.
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Please go through the following PDF attachment.
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Hi,
I need to convert phytoplankton (cells/ml) to phytoplankton biomass (µg C/L) to compute in water quality modelling. In literature, I found biomass transformation for microrganicsm and conversion factor of phytoplankton (as C:Chla ratio). I am not sure that i can use this equation for phytoplankton biomass.
Note: I have phytoplankton as green (Class Chlorophteae) and diatom (Class Chrysonphyceae).
Literature: C. Ferrier-Page`s, J.-P. Gattuso (1998) Biomass, Production and Grazing Rates of Pico- and Nanoplankton in Coral Reef Water (Miyako Island, Japan). Micro Ecol, 35: 46-57. DOI: 10.1007/s002489900059 Please give me some advise
Thank you
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Hello everyone,
I write to ask if this image is fitoplancton? if so which phylum and genre? This sample was taken from fresh water from the São Francisco River, Brazil. not measurements, because I don't think so.
Sincerely,
Ranielton de Moraes
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Unfortunately not! This photo was taken from a sample that has already been dismissed.
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Hello guys, I write because I need to identify this genre of phytoplankton
follows and image on and the measurements
colony length is 18.15µm, width18.975µm, radius is 10.755µm
I believe the genre could be Aphanacopsa
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thank you my dear, I believe it is this genre.
Ranielton
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For calculating Q-index for phytoplankton functional group can we consider only the water depth or should we also consider the area of the aquatic body?
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" Q-index for phytoplankton "
Which paper/report did you see? Can you send? I've never heard of it before.
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Hi all!
I have the output of amplicon sequencing data (18S) for algae species from two sites. I am looking for a method that is not TOO complex where I can analyse which species are correlated with the presence of my target species.
Thanks in advance.
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by saying correlation do you mean what are the other organisms present in the two samples apart from your target organism?
For analyzing amplicon sequencing there are quite a number of programs and pipelines (QIIME2, MOTHUR) but this requires special environment, knowledge of Linux based languages and are a bit complexed.
The easiest method you can use is the GAIA platform (https://metagenomics.sequentiabiotech.com/). It is user friendly, more accurate and fast. you can use it for free upto 2GB of data. if you have more than 2GB of data then you nedd to avail the paid services.
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We usually use Formaldehyde to fix phyto and protozooplankton samples to be analyzed through FlowCam. However, this time we will conduct a plastivory experiment in Antarctica, and the samples to be analyzed in FlowCam will contain phytoplankton and also microplastics. Microplastics will be later aswell observed by Raman microscopy, and one requeriment to observations through Raman is not to use formaldehyde. I think that may be ethanol can shrink phytoplankton cells? the objetive is to count the cells.
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What is the possibility of separating the plastic particles from the plankton at the point of collection and then using two different preservation media? It might be worth investigating by looking to see how plastic particles are concentrated now from water samples. Low velocity flow through centrification?
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I found a bloom of cyanobacteria with filaments that look like Sphaerospermopsis aphanizomenoides if you see the dispositions Heterocyte_AKinete_Heterocyte and others features but i found some filaments with an elongated apical cell (fusiform) (i have tried to find Heteocytes or AKinetes but i didn't find).
Some suggestions?? Perhaps Aphanizomenon favaloroi?
Phytoplankton from a Reservoir fixed with lugol
Thanks in advance
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Thanks Silvia Haydee Otaño for your answerd. It s true that my filaments looks diferent as those from your publication. But in the publication : First report of Aphanizomenon favaloroi ocurrence in Europe associated with saxitoxins and a massive fish kill in Lake Vistonis, Greece from Maria Moustaka-Gouni et all Marine and Freshwater research, 2016,67,1-8 there are some filaments with spherical akinetes and at both sides.
But it is true it must be another Aph/Chrysosporum or and hibridus
Thanks
Maria
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I have been using different kits and heat lysis methods but the DNA yields are normally low , even when I run the PCR on those samples, there us normally a smear of RNA with no bands at all or sometimes when I get bands the spectrophotometer readings are not quite consistent
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No amount of testing of different kits/methods is going to improve the quality of your input ("shit in shit out"). Is the DNA fresh, or has it been preserved from fresh and the number of cell input is high, then to be honest most methods will give you what you need, obviously with a slight variation (this is also dependent on what your doing downstream). Personally CTAB with phenol chloroform is the best, but for a kit Qiagen DNeasy plant works well. If you're getting a smear then do an RNase treatment. Lots of papers explain these methods clearly for protist. Once you have DNA (in H2O or tris, EDTA is an inhibitor) run a Qubit to quantify and a gel to qualify. Is the DNA fragmented then you can forget PCR, especially if it is long range. If you have high weight DNA and you'r PCR isn't working then the problem isn't the DNA but an element in the PCR. The first guess being the primers, but that's a whole new question ;)
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I'm currently conducting a research on the phytoplankton composition of a series of ponds and water streams in moutain areas of my state (Bahia, Brazil). These organisms in the pictures are very frequent in my samples, but I can find no information on them. Any specialist would help me out with this? In the pictures they sometimes appear in a tridimensional manner, some other times, less frequently, as bidimensional.
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I have no idea about the fresh water organisms as my research area is different.
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identification name of diatom (phytoplankton).
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The alga is a taxa of Dinophyta: Ceratium hirundinella.
Best regards
Lothar Täuscher
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I was wondering about the role of free fatty acids in dinoflagellates, more specifically the symbiodiniaceae? What are the metabolic pathways and where are the different types of lipids usually manufactured?
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Thank you Dr. Mukherjee
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For my project looking at the biodiversity of phytoplankton in the Arctic, I have calculated Hill numbers and Average Taxonomic Distinctness on my samples, and they both tell very different stories so I would like to include them both. I am just stuck as to how I can justify using both, and if I can't, how do I choose which one to include? Has anyone else ever had a similar decision to make?
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It's common to report more than one index. Diversity indices aren't like statistics where you have parametric and non-parametric methods, and only one is appropriate based on the data. They are attempts to describe different aspect of diversity, such as richness, evenness, rareness, etc. Ultimately, it's up to the researcher to interpret what the index is saying because it's just a number from a formula that is meaningless without context and a description. The tool needs to fit the question and what you're seeking to find.
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Since I clicked phytoplankton images which are in 2D format I am facing difficulty in measuring the 3rd dimension mostly related to apical section girdle view
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Yes
It don't have an open access
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I'm currently conducting a research on the phytoplankton composition of a series of ponds and water streams in moutain areas of my state (Bahia, Brazil). These organisms in the pictures are very frequent in my samples, but I can find no information on them. Any specialist would help me out with this?
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I agree to Nicolas,
It seems to be trichomes, maybe from bromeliads, which are pretty common in Bahia mountains. I have found these also in phytotelmata samples.
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The zooplankton density estimated in this study ranged from 354-771 cells per ml. That means it is 354000-771000 cells per liter. If you see the available literature from Indian coasts as well as from the same Kalpakkam coast, zooplankton density generally will be in the range of 200000-600000 cells per 10000 liters of seawater. Even many authors have reported similar densities for 100000 liters of seawater. So its unimaginable how such huge numbers were arrived.
Generally, a phytoplankton bloom with 700000 cells per liter density can be seen in naked eye as a distinct layer of green, brown or red colour on sea surface. So, with this high density of zooplankton reported in this paper, the sea will be full of zooplankton. With this density, if you take one liter of seawater, 20-30 % of the volume will be occupied by zooplankton considering the presence of gelatinous species encountered by the authors in this study. Practically, it is just impossible.
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Numerical estimation of planktonic species are performed by many, but it is indeed a sorry state of affair that many of such reports are the results of extrapolated data obtained from very least volume of water sample and that too without establishing a mean data. Normally manual or instrumental enumeration of species assemblages, if performed on only 0.5 to 1 ml of water sample, results in amplification of the data when extrapolated to a litre of water and often the data exceeds what would have been actually present there.
With this being written, it is also possible for many workers to simply misidentify the more mature copepodite stages of mesozooplankton as adults and that too often yields exorbitant densities.
Keeping the above statements in mind, we need to consider the fact that aquatic system in highly dynamic and data procured from one such environment can only be contested upon by being at the same sight at the same time, which practically is impossible since the planktonic assemblages varies significantly based on the circadian rhythm as well as the biogeochemistry of the ambient ecosystem. Also the presence of warm discharge water at the vicinity of nuclear power plants might have triggered such a phytoplanktonic bloom as befitting the number of zooplankton reported.
Unless consistent data of similar magnitude get reported, it will not be prudent to discard (no matter how outrageous it appears) nor incorporate such data in the more practical data pool used by the concerned personnel. Doing either without absolute evidence to disregard the other will simply lead to impractical vilification and unwanted situations. In cases such as this, ignorance is a bliss.
Regards,
Dr. Abhishek Mukherjee
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Size-fractioned absorption coefficients of phytoplankton(aph) has been estimated by several algorithms in the works of Devred et al.(2006), Brewin et al.(2011), and Varunan et al.(2015). However, we can not find the information about how to meansure in situ values of size-fractioned aph. In addition, can we empoly size fractioned filtration as same as PSC measurement (Pass the sea water through the 20μm and 2μm filter, and retaied on the 0.2μm filter)? Or, there are problems in this method?
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Dear Lin,
For details on best practices for measuring particle absorption (size fractionated or otherwise) on a filter pad, please see: http://ioccg.org/wp-content/uploads/2015/10/absorption_protocol_forcommunitydistribution-sept2017-2.pdf. To use the method you described above, a consistent volume is required for the whole sample and filtered sample, which should be compared to a blank or baseline sample of the same volume.
Best of luck!
Sasha
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In order to estimate the sources of particulate organic matter in a large freshwater lake. I measure the C/N ratio and C13 and also the n-alkanes as the biomarker to eluciate the potential sources of POM.
However, the results is very confusing. Because most of the POM have appraent peaks at c27 or c29 of alkanes profile (terrestrial signal), which have low C/N ratio as 3 to 5 (phytoplankton signal). I can understand that sometimes the clay particles from terrestial soil will have lower C/N, which are already reported by many references.
But these particles are also have low POC/chla ratio (<100), and a very good linear relationship of POC and chla was observed(R2>0.8).
Can anyone give some clue or suggestion? Thanks a lot.
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Yes, I am totally agree your comments. As the sampling area is a big shallow urbanized lake, many sources was generally mixed and biodegraded. I have already tried to apply the proxy as your recommend, and I got a higher contribution of terrestrial and sometimes petroleum contribution. But what I am confusing is that the particles have lower C/N ratios and relative low POC/chla (<100 microgram per Litter) as I said in my questions. And actually I am not expecting the higher contribution of terrestrial, because the lake is highly eutrophication, and cyanobacteria bloom (I thought they are main contributors to C17 in my case) is serious issues in this lake. So I am wondering if the alkanes indicators are still robust in my case, since I saw some articles showed the diagenesis effect could cause higher contribution of long chain n-alkanes in sediments, even though the allochthonous inputs is few.
And I am very grateful for your suggestion, I will try to test them. Could you tell me the approximate retention time of these compounds basing my TIC graphs, it will be helpful for quickly locating them.
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what is the appropriate sampling design for the caracterisation and the study of the spatial and temporal variability of coastal phytoplankton in a bay in response to hydroclimatic conditions? knowing that this is going to be the first study of this kind in this region In the absence of preliminary studies on the study area, I decided to opt for a systematic plan. what would you say? is it possible to work with a purposive sampling method, knowing that the bay has an estuary and is subject to an ocean current?
Best wishes
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You can go through this book
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Does anyone know how I can prevent a lake to be green?
I think this is because of phytoplankton growing in water.
This lake has some birds which drink from it and the answer must do not damage the birds.
thanks
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agree with Marcos Sarmet Moreira Barros Salomão ... the lake water has high content of nutrients... first of all you have to find out the source of nutrient and if possible stop it. It may take time.
to get quick result you can manually collect them and use them as bio-fertilized. yo can also culture herbivore fish species. it will solve your problem and will not harm bids. again, the permanent solution is stopping nutrient flow from outside the lake
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To calculate the surface to volume ratio is relatively easy for unicellular species, coenobiums, and filaments, but, how do you calculate this relation in the case of phytoplankton colonies (e.g. Microcystis sp)? I was thinking that if one calculates the volume and surface of the whole colony the ratio could be sub rated. I would really appreciate some help.
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If the query is to find the surface to volume ratio of a phytoplankton colony then the answer is pretty simple. One needs to simply measure the dimension of a uniform number (say 50) of cells ranging from the smallest to largest to draw up the mean value. Once done, the mean surface area/volume of random individual cell could be extrapolated based on the arrangement of those cells within the colony and the surface area as well as volume data can be obtained.
BUT,
if the question is intended to procure the biovolume data then, the cells as well as the mucilage or exopolymers as well as intercellular connectivity etc all need to be considered in a colony.More accurately the carbon content or biomass data can be used to generate bioviolume data or vice versa.
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some pictures were repeated
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3 and 14 - Cilliate (maybe Colpoda)
4 - Dinoflagellate (maybe Gonyaulax)
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This organism belongs to a sample of freshwater phytoplankton collected in the end of 2018. Does it depict asexual reproduction in Staurastrum or it's just an image imperfection?
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If the centrally smaller and rather hyaline structures are semi-cells then, judging from their large chloroplasts I think IT IS an image of Staurastrum undergoing asexual reproduction. If you can ascertain the centrally located pyrenoid within the chloroplast in your sample then without a doubt it is an instance of asexual division of desmid cell.
Regards,
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i need control organically
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You may go for Plant extract or nutrient supplement like single super phosphate to crash it naturally by over crowding that.
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Hello,
I performed some HPLC analysis in order to find pigments in my green algae (Scenedesmus). I recognised the peaks using retention times and size of area peaks, using as reference the Mantoura and Wright (1997) book. I would like to transform my area in mg/L but I don't have standards for the pigments, only for Chl a. Is there a way to do it anyway without standard?
Thank you in advance
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Dear Dania,
To calculation the pigments concentration without calibration curve is impossible. Because of at first you should calculate the equation (Y = aX + b) based on standards, then by using it you can gain the final data. 
In one way you can report your results in percentage and comparison between your samples. In another hand, you can use an alternative procedure such as a spectrophotometric method. I attached the original paper for the spectrophotometric method, Lichtenthlaer's protocol, for your reference.
Sincerely yours, Homayoon.
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I am working with Cyanobacteria (Brackish water).
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Be sure when you surfing in the net, most of the web site are misleading...
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I just want the name of the methods....
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If you fix it with %30 formalin it is not possible...
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Hello Carmen,
I am writing a project - to apply for a postdoctoral fellowship - about the effect of microplastics on marine microorganisms (I am mainly interested on phytoplankton and bacteria), could you suggest me any related publication? Thank you very much!
Best,
Isabel
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Many thanks Fatih!
All the best
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Dear Researchers,
i found this organism from marine source, sorry for not providing good quality photograph. this organism i identified as Peridinium member of Dinophyta. can anyone confirm the species. and recheck the identity of the genera. 
thanking you in advance
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Paint with Calcofluor and look at the plate under epifluorescent
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I am making corrections to a database of observations of phytoplankton samples. the point is that he needs to convert the observations into density (cel / ml). I found a formula that mentions. N = X * [(A * d) / (a ​​* V)]. where N) = cel / ml.
X) = Observed A) = Area of ​​the sedimentation chamber. d) = Area of ​​the optical field or grid. a) = dilution factor. V) = sedimentation volume. I was also given this data: Area of ​​the camera = 490 mm2. Optical field area = equal to the area of ​​the camera because it was observed complete (full sweep). dilution factor = 1 (sample not diluted). V = Sedimented volume (50ml for all samples).
in several samples, 1 to 30 cells were observed in some species. my question is: is it valid to say that when 1 cell was observed, its corresponding density value is 0.02 cel / ml? or is there any correction to the formula?. I thank you in advance for your answers.
PD: they only made 1 observation per sample, under a 25x magnification and total observation of the sedimentation chamber .
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It is helpfull for you...
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These Imaging FlowCytobot (IFCB) images were taken during a December cruise in the Santa Barbara Channel during the Thomas Fire. They were imaged after tripping a fluorescence trigger. These species appear at the surface and at the deep chlorophyll max. The cells look like they are in various stages of dividing and were maybe pulled apart by the IFCB during intake. Any help with identification would be much appreciated!
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Those looks like coccolithophores, probably shed their calcite discs..
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Hello, We are looking for our "small" lab a solution to replace formalin and its health risks by another conservation for phytoplankton. We use lugol for storage <1 year and placed in the fridge, but in terms of long-term conservation we currently only have formalin. We also do not want to use glutaraldehyde, which also poses problems of toxicity, handling and storage. Do you use other products? had you ever test ethanol with phytoplankton storage? if yes to which volume? Thank you in advance for improving safety and health at work
Nathalie NOUCHET
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%2-3 Formaldehyde buffored with borax...
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