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Zooplankton Ecology - Science topic

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Hello! Between mid-April and throughout June2017 we carried out an extensive sampling to estimate sea urchin settlers through collectors placed on the bottom floor along the Sinis Peninsula (Westcoast of Sardinia , Italy).
We placed 100 collectors at five metres depth, on rocky bottom and Posidonia oceanica meadows, inside and outside the Marine Protected Area of Sinis (according to the method described by Tomas F, Romero J, Turon X, 2004) to evaluate settlement and recruitment of sea urchin Paracentrotus lividus in two contrasting habitats in the Mediterranean (Marine Ecology Progress Series 282: 173-184). Altogether we collected about 500 samples kept at -20 deg. in 70% alcohol. Moreover, we characterized sampling stations calculating habitat and landscape metrics.
However we found many other species of organisms, especially polychaetes, molluscs, crustaceans, other echinoderms, etc.
At the moment we lack resources to perform taxonomic work on these communities.
We are happy to send over the samples to anyone who could be interested. Considering we do have all the environmental data metrics, it would be great to identify biodiversity hot spots in the study area once we have the taxonomic data.
If interested, please contact me at: s.farina@fondazioneimc.it
Cheers!
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It's too late, but I will be interested
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For community studies like species succession, variation in composition, especially for plankton and benthos, what are the appropriate statistical methods? One such method is MDS with cluster overlay. Similarly what else can be applied for such studies?
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Yes, You can use many methods of cluster or ordenation analysis. May be the assay with PRIMER software could help you and select the methods that you want.
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I made a study on the effect of two factors (A & B) on a variable response Y (chlorophyll rate) in mesocosms. These treatments with two modalities (A1/A2 & B1/B2) were crossed to create four different treatments : A1_B1 / A2_B1 / A2_B1 / A2_B2.
And i made 3 replicates per treatment.
However the chlorophyll rate varied according others factors especially zooplankton communities.
Thus, i obtained a huge variability between each 3 replicates per treatment. And to reduce it, i was wondering if i could divided my chlorophyll rate by the total amount of zooplankton / or the amount of cladocerans because these are the communities that contribute most to the decrease in chlorophyll. (Or even just divided by the amount of daphnia because they were the more abundant cladocerans present in my study over the time). My idea is to reduce the variation of zooplankton communities between replicates and thus to reduce variability of chlorophyll per treatment to then be able to see the effect of my treatments on chlorophyll ?
I hope I am not too confused and thank you in advance for your help.
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I not so familiar with the probes used although I have used them but I might suggest developing some calibration plots using standard wet chemistry extractions with acetone or even the hot methanol extraction.
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Can  you help me identify this Hexarthra?
Pouvez-vous aider à identifier ces Hexarthra!
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Most probably this is male rotifer of Hexartha. I am now in Australia, my laboratory is in Bangladesh. So, you please go through the literature that I cannot do from here. Consult with Fresh water Biology of WArd and Whipple.
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I obtained a cell during  nematocyst isolation from the oral arm of Thysanostoma loriferum( Scyphozoa).can anyone help me to identify this cell
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Thank's for all help me to identify that cell.
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terrible fotos - but after postabdomen, and body shape it looks like D. deserti .... see foto Hudec 1993.  D. similis is really different   igor
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Copepodes , plankton ; Acanthocyclops robustus
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hi Salah MAhdi ;
thanks for al this articles 
greetings
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This small crustaceaen appeared in a zooplankton sample from a small reservoir in Costa Rica. Unfortunately we were not able to find it again to take a better picture. We would appreciate any hints about its identity.
The zooplankton net probably touched the bottom or the littoral zone before the hawling because the sample contained some organic debris, whcih could be observed to the left of the organim.
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It does not look to me neither as a cladoceran, nor copepod or ostracod. Because of the separated eyes and bifurcated caudal appendix, it reminds me of a juvenile isopod, but it's not sure at all from that picture. I can't see the suckers if it would be and Argulidae, but I have no experience with them.
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The zooplankton I had in mind specifically are copepods found in lake communities. From my research, I found that their presence can be a generally beneficial factor, mainly because they prevent harmful algal blooms.
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Strangely enough, no previous answers actually target the question - what negative consequences may arise with increase in copepod abundance?:) I would not seriously consider oxygen depletion in the epilimnion of the large lake....But this is a very good question. It is commonly assumed that the more zooplankton - the better (=higher trophic efficiency, etc.), but this is not just this simple...
What comes to my mind as a possible negative consequence of the situation that is described is:
- possible blooms of infectious deceases and pathogens that copepods may carry as primary or intermediate hosts;
- food web alterations for other primary consumers (competition) or secondary consumers (cascading effects);
- increased grazing of algae that are important food source for benthos relying on high sedimentation;
- transfer of algal toxins (if any) to higher trophic levels should the copepods bioaccumulate these toxins.
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working on sparids diet i'm looking for a site or link for identification of preys mainly:
-crustacean, annelids, fish, echinoderms, algae...etc
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All very good advice!  I dissected flounder juveniles and knew what species the single eyeballs in the gut were from.  I was able to infer how many of that species had been ingested! Good Luck!
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I have a preliminary names of all the organism that i found on the gut of freshwater fish i just need to verify this images. please  help me because it is part of my thesis paper.
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it helps a lot sir..thank you for the time and for identifying it..have a good day to you sir.
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Samples were collected from a highly turbid river and contain much too much sediment for efficient taxonomic processing of individuals. Samples were filtered through a 75 micron mesh. Simply filtering the sample with a courser mesh net won't do, as we would lose too many small zooplankton.
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The Ludox density gradient centrifugation is probably the most appropriate method for your purpose.
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Is there any good resource of ciliates that talks about species specific feeding habits (eg feeding type, trophic role, clearance rate)?
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Dear Lennart,
may be i can help you. Cannot do now any complicated work because gathering with family for Suth-East Asia (Thailand, Indonesia, East Timor, Malaysia and after that into East Africa). This country science is over so may be will try smth other. It all cost 6 month period, but I will try to be in permanent contact with colleagues, except of climbing Cota Cinabalu etc. So, I'm attaching for you my database for ciliates. Please, do not distribute, as it will be for a patent attaining (still have no time to prepare). We are using it (one of a lot of databases) for calculating structural and functional parameters of communities. Open it like txt file. For help look attached file. Can send you program, but it needs experience to use. Moreover, the database for the Baltic Sea should be improved.
Previously we use some sub-program I wrote for the prim. pro. decomp. of benthos, and peryphiton but now V. Pliashechnik elaborated Excel program to do it.
Frankly,
Andrey
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We have been monitoring a temperate lake during the winter and observing Daphnia under the ice, when normally they would not be found in the water column. Some of which still have asexual eggs.  The system is hyper-eutrophic which is leading us to think perhaps food conditions still permit growth even though temperature is cold. 
Has anyone else observed Daphnia in winter or under the ice in lakes? Thanks.
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Hi Brian
There is some literature also from other counties on daphnids spending the winter as adult females. For instance, Larsson & Wathne (2006) reported adult females during winter in oligotrophic mountain lakes.  They claimed that females that produced ephippia in the autumn have less reserve energy at that time, than those  spending the winter as adults. Furthermore, Lampert et al. (2010) hypothesized that females can exhibit a mixed strategy, first produce ephippia, then spend the winter in an active state. Hamrova et al. (2011), however, found strong clonal variation among populations regarding their reproductive strategy during unfavourable conditions. Thus, high food density appears not to be a prerequisite for adult females under ice in winter, but perhaps rich winter conditions may improve the survival of the adults during winter. Larsson & Wathne (2006) reported high mortality towards the end of the winter in oligotrophic, alpine lakes and assumed that this is due to lack of reserve energy in support of your hypothesis.
References
Hamrova et al. BMC 2011 11:231
Larsson & Wathne (2006) Arch Hydrobiol 167: 265-280
Lampert et al. (2010) in oligotrphic mountain lakes. Limnol. Oceanogr., 55(5): 1893–1900.
Bror
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I am looking for your recommendations of trinocular microscopes to observe behavior (movement) of aquatic mesofauna / meiofauna in 6-, 8-, 12-, or 24-well plates.
And with preferably same scope observe internal morphological responses to chemical exposure.
Thanks,
Lou
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I've been happy with the Olympus SZX for freshwater zooplankton. I have also used the Nikon series that is similar to the SZX. In my opinion both are great but the SZX will save you money and you get the same quality. We switched out the LED base to a different version though, because we wanted a to be able to tilt the light source with a mirror to adjust the contrast. Which really helped for identification.
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I'm wondering if there is a published toxicokinetic model for D.magna (or similar organism) regarding hydrophobic contaminants like PCBs for example. I have a feeling there should but I can't seem to find it. Any tips are greatly appreciated.
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ThankLena and Edgar. Extremely helpful! :)
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Sample was from mountain lake in Ukraine (april 2015, under ice).
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Larisa,
 look like some simple Difflugia. But needs to be measured and from different points of wiev ! Look, please, some articles about Vorochevo lakes and Svidovets lakes from my site, altitude about 660 m, and 1400 m. I studied it enough well, but hardly to identify from this photo. Testate amoebae needs to see their oral form and collar< important is if flattend body, some "neck" like Pontigulasia. Can ask Volodia Pliashechnik from Uzhgorod (he has site) or if need perfect qualification call Prof. Vassil Golemansky. Anyway perfet key of mazei & tsiganov in Russian. i made the very good PDF, just put for smbd like reply for question.
important if this lake has some water flows in & out. if no, will be like swampy area with special faunal list...
Andrey
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To develop citizen science, we want test various safe methods to conserve zooplankton samples on sail or motor boats from couple of days to weeks, if possible not to much expensensive.
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50 g of I2 (metal), 50 g of KI, 50 g of CH3COONa, about 1 g of phenol, q.s DW to 1 l. Add to sample by small portions until it look like strong tea. Conserved samples can hold out from several month to year in cold place (it may be need to add conserving agent if sample color become pale).
Rotifers without rigid shell (Asplanchna, delicate Trichocerca et al.) will distort.
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In the upper 100 meters of the waters south of Cape Verde (Eastern Atlantic Ocean) I collected a number of pyrosome speciments. Can anybody confirm the identification for Pyrosoma atlanticum?
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This looks like a small specimen of Pyrostremma agassizi.
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It was collected in a stream with a strong current.
Thank you!
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It's often difficult to identify illoricate rotifers which can require to be observed alive and active in order to see them with their appendages extended (foot, head, antenna, spur).
Your rotifer could be a bdelloid and you should look at the trophus to confirm that.
If so, the following papers can be usefull :
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Dear Researchers
I had 3 data group. environmental data (Temperature, Oxygen, pH, EC and Turbidity), zooplankton community and growth rate of a fish. All data belonged to a one pool. Now I tried to find a best model to describe the relationship between number of zoopnaktons, environmental data and growth rate of the fish. what is best statistical method? Is GLM applicable?
Thanks for your help 
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Heiarchial cluster analysis, component analysis can be done to study the direct and the indirect interaction and interrealtion between the zooplankton community and the fish growth rate.... SPSS and SYSTAT can be used for the same...
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Some says it as a rotifer, some as a Tintinnid. & My doubt was is it a phytoplankton. Please help me in identifying this organism.
Thanks in Advance
ANILA AJAYAN
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This organism lacks median spines unlike Keratella taurocephala. 
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I think it is a type of Cyanea , but I can't find any species with such long primary tentacles. Thank you in advance for your assistance.
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It is rather difficult to separate between Lobonema and Lobonemoides without observing canal structure. As far as my experience, however, it would be Lobomemoides robustus. They are very abundant in the Gulf of Thailand targeting commercial fisheries.
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from Karachi coastal waters
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thank u Pal
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Could anybody help me the name of the 2 zooplankton? or their family,or order?Anything will be helpful to me . Thank you so much. Additionally, if anybody need other photos on these two zooplankton, please message me.
The length of them are both ca. 5 mm.  
Notes: the zooplankton1-1  whole body is nearly white color;
zooplankton2-13 former half body is nearly white color ,but the later half body is nearly pink color,approximately iron red color. 
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1st one Subeucalanus attenuatus??
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I am looking for studies about hyponeuston and in particular I would like to know if someone studied mesozooplankton in the surface waters (first 10-20 cm) of the Arctic.
Thanks
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Dear Valentina,
In the attachment please find copies of papers, which may be interesting for you.
Take into account that they are quite old, and some of the taxonomic information (species names) have changed.
Best regards,
Slawek
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We observed a shift from Kellicottia to Keratella along a trophic gradient (other studies have observed the same pattern). What mechanism  can explan this shift?
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perhaps you might find an answer in the enclosed aricles, including the thesis by Virro.
why  they are typical of eutrophic  and meso-to oligotrophic conditions has apparently been left to the curiosity of other specialists. at a guess, feeding habits or feeding efficiency, since they may appear in fairly high numbers, but guesses are not good enough for publication (and therefore not as answers to your question)
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How can I get a complete identification key of Zooplanktons ?
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It depends on the zoogeographical region, freshwater or brackish or salt. General keys are based on the most typical (in author's opinion) species. In first approximation such general keys can be used, but you should support tham by specialised keys, e.g. with regional or world fauna books. In post soviets countries f. ins.  when identifying Rotifers we use normally perfect Kutikova book, when have to do with Chidoridae – Smirnov Fauna of the world (1971) (in Russian). As well, Cyclopoidea by Monchenko, Harpacticoidea by Borutzky etc. So, you should define more accurately you interest.
Andrey
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This animal was caught in the eastern central Atlantic (seems to be complete) in depths between 100 and 600 meters. There was just individual of it. Can anybody identify it?
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This appears to be a pelagic polychaete with an everted proboscis.  Identification of genus/species would likely require details of the jaws and arrangement of the setae which is not possible from the photo.  Perhaps someone is familiar with the species already?
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This specimen is found in a pond that connected with seawater.
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Thanks very much for Mustapha and Eugenia's kindly answer. After comparing the specimen and the image of Chaemorpha, I think it really should belong to genus Chaemorpha.
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Zooplankton are, by definition, drifters in the ocean. Therefore, they are often associated with different water masses and can be ideal indicators for assessing ecosystem status. More specifically, what can they really indicate, how do we incorporate zooplankton indicators into ecosystem assessment framework, and how these indicators can be used in marine policy?
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Hello Alessandra,
I strongly advise you look into William Peterson's work with the NOAA Northwest Fisheries Science Center. His research has been integral on the effect of the Pacific Decadal Oscillation (PDO) on zooplankton community composition with emphasis on fisheries management. 
Just like temperature, zooplankton community composition can be used as a metric for stock success, individual growth, and overall fecundity. PDO phase shifts correlate with variation in seasonal upwelling and temperature regimes, resulting in zooplankton community changes that dramatically impact energetic constraints on foraging fishes with carryover effects for piscivorous species. Zooplankton community composition has also been used as a proxy for ecosystem health and assessment of susceptibility to climate change in more recent years. 
Bill Peterson would definitely be the person I would try and contact for specifics on the how's and why's of how these metrics are applied to fisheries analysis and policy.
Cheers,
-Thomas
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I am talking about SW part of black sea coast. I think the sampling depth for the vertical hauls must be 0-10m - 10-20m. I do not know if it is a suitable depth for good sampling. I know that depth depends.
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You should select your depth range based of actual pycnocline layer.
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Concentrations of PCDD/F, DL-PCB and NDL-PCB are lower in zooplankton (primary consumers and lower-trophic-level invertebrates) than in phytoplankton (primary producers).
I’m interested in levels of these substances in zooplankton (e.g. copepods), especially from Mediterranean area. I found a few publications, some a bit dated.
In particular which concentrations can be considered of concern at this marine food web level?
many thanks
stefania
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Hello Stefania, you can take also a look at these two studies  performed in the MED, one focusing on biocumulation of PAHs in Zooplankton and the other on non-DL PCBs and OCPs in plankton. Maybe interesting for you. Regards.Javier
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These are copepod grazing experiments, where the particle size spectra and abundance were measured with a coulter counter particle counter in initial samples, and final control (no grazer) and treatment (with grazers) bottles.  
This is a new area for me, any help is greatly appreciated. 
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Aha, I misunderstood. Some do test that, you could e.g. make a t test between grazed and control treatments. But i usually do not. Maybe I would if there is no clear grazing effect to be able to state "no significant grazing" Regarding the shrinking I would not worry for short (over night?) incubations. But several common colony forming species do split up in response to copepod grazing. E.g Skeletonema (Bergkvist et al 2012 L&O) Phaeocystis (Long et al 2007 PNAS), and Alexandrium Selander et al 2011 PNAS). At least for Skeletonema and Alexandrium the response typically takes longer than an over night grazing experiment to develop fully. If you do total bio volume it should not matter anyway, the cells are still there. So this probably added more confusion than solution, but I think normally stats is not necessary to prove grazing in a grazing experiment, rather to prove differences in grazing between treatments, prey etc. Best wishes /Erik
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I need to know if the strastigraphic range of the radiolarian species Belowea variabilis WON is exclusively Carboniferous or could extend to the Middle/Late Devonian?
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Well, I distinctly remember this radiolarian species extending down to Devonian. Please do check up literature.
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I found negative correlation between cladocera as all and calcium concentration
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We have been doing quite a lot of work on this topic.  If you go to my lab's web page:
and Click on publications (although not totally up to date) - there are several of those papers there.  See papers especially with Adam Jeziorski as an author.  See also our recent Proc Roy Soc Paper:
John Smol
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I'm working on latitudinal diversity gradients in these taxa (copepods and cladoceran) and would like to know if it is safe to assume that speciation events have little effect on current diversity patterns in zooplankton across Canada.
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Thanks a lot Alexey!
Best regards
Renato
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Thanks in advance for your replies.
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I have done some permanent slides using microscope slide and cover slip and nail varnish. If the object is not too big (most cases on mesozooplankton it is too large) then it should work nicely. Just but a little drop of fixated (4% formaldehyde or lygol or spirit+clycerin) plankton species on microscope slide and cover it with cover slip and then cover the edges of covr slip with nail varnish (transparent is the best and some companies make better varnish than others). Let the varnish dry and your slide would be ready to preserve!
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Hi Friends,
I found this sample(which is attached) along with the phytoplankton samples collected. Suggest me weather its a kind of plankton or some other thing. If its a plankton help me to identify its name.   
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I am fairly sure that it is a cycloid fish scale, as others have suggested. We frequently encounter them in plankton-net samples. They (1) get knocked off of fish that are caught by the plankton net and (2) exist in sediment largely as the result of predation events; sedimented scales may be easily re-suspended into the water column, where they may be collected by plankton nets.
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Every September since 2003, students in my senior class in freshwater ecology take net plankton samples from deep, soft-water Lochaber Lake, Nova Scotia, Canada. The lake is undergoing a transition to a more productive condition, characterized by intense blooms of Microcystis aeruginosa.
This year, students observed oblong, red inclusions within the bodies of copepod nauplii from the lake. I have not seen these before and I have no idea what they are.  There were as many as 6 within the body of one copepod.  You can see a couple of low-resolution photographs on my web site at http://people.stfx.ca/btaylor/WebPage/Barry%20Taylor.htm.  Are these bodies familiar to anyone?
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It looks like lipid droplets with carotenoid coloration
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Dear Fellow,
I have examined many plankton under phase-contrast microscope, but unfortunately, I could not identify some of them, therefore I kindly need your help, plankton expert!
Thank you so much!
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The definition of the pictures is low. Nevertheless it doesn't seem to be organisms.
It looks like pieces of detritus usually found within the suspended particulate matter.
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There is no authentic report of the total number of rotifers reported from India. Anyone having any idea of the approximate numbers and the reference of it.
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Contact Prof. B.K. Sharma, Dept of Zoology, Northeastern Hill University, Shillong. He may be able to help.
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Recently, I downloaded ZooImage software for image analysis of freshwater zooplanktons. I want to know if anybody has used this software and whether this zooImage software is reliable ?
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thank u harris.
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I'm looking for studies or simple nutritional profiles on live, powder form, and concentrate versions of phytoplankton. To further study the effects on feeding copepod cultures that are feed those versions of phytoplankton.
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Hi everyone.
I can just give you some titles of studies where there tested
1. the fatty acid differnces of phytoplankton under changing nutrient ratios (Bi, Arndt & Sommer 2014: Linking elements to biochemicals: effects of nutrient supply ratios and growth rates on fatty acid composition of phytoplankton species)
2.The differences (Fatty Acid composition) of between phytoplankton species for copepod development (Arndt & Sommer 2014: Effect of algal species and concentration on development and fatty acid composition of two harpacticoid copepods, Tisbe sp. and Tachidius discipes, and a discussion about their suitability for marine fish larvae")
It might help you.
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It was found in a marina located within a south coast estuary (South Africa). It forms a red/rust coloured layer. I do have additional pictures available. 
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Dinoflagellate Prorocentrum cf. rhathymum [I can see the diagnostic small spine on at least one cell)
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I am working on freshwater zooplankton so I would be very grateful if somebody could give me some idea for using the best stain in identifying freshwater zooplanktons.
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You can use Lugol for that.
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We found zooplankton species richness increasing whereas abundance and biomass were decreasing. Have you seen something similar and what could be the reason?
Any references and explanation would be helpful. The research area is very shallow water in brackish-water Baltic Sea.
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Hi Lennart, inverse relationship between these metrics is well documented, particularly for zooplankton inhabiting brackish water, or, water of varying salinity (in time) such as in classic estuaries.  Before adding my 2 cents worth, can you tell me more about what is meant by "increasing"?  I take it you mean diversity has changed over time yes? What time scales, hours/days/weeks or by season/ year-to-year? Have you noticed a concomitant change in any environmental variables?
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My zooplankton samples occasionally contain masses of chain forming diatoms (also organic material) that are virtually impossible to remove from the sample before being subjected to the biomass determination process (gravimetrically, dry weight). I am seeking advice on methods to be used for separating, to some degree at the least, this non-zooplankton component, other than by way of manually picking.  The latter method, however effective, is due to time constraints, not a viable option for this particular programme.  Any advice given will greatly be appreciated.
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Dear Shaun,
To my point of view, we first need to know if you want the biomass by family or genus  category, or by the entire zooplankton community. I will answer to the most accurate level of biomass estimation: the family/genus level. I suggest also to use the digital imaginig system (probably another system than zooscan that s pretty expensive) but rather a commercial scanner like Epson V700 and plastic tray) and estimate biomass with a software like silhouette digitizer, the software proposed by Joanna Strzelecki or zooImage. The last one is able to accurately recognise semi-automatically mesozooplankton up to the family genus level (see Grosjean et al. 2004) and use conversion factors to estimate biomass.  Its possible to automatically discriminate particles other than zooplankton but you will need to dilute quite a lot your sampling to avoid the overlapping between copepods and chain forming diatoms. So you will need to use sometime the method proposed by Kalevi Salonen. You can also use the method of José Pedro Marín to preprocess and clean your sample..Its quite accurate compare to traditional methods. Time to dominate the entire system and software: 2 months. But u will save time for the next surveys.. Hope it will also help you.
All the best
Pascal
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Is there a distinct morphological difference between Megacyclops viridis and Acanthocyclops robustus? Is it possible to be observed  A. robustus with very very rounded cephalothorax like M.viridis.
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Stefan,
the shape of the cephalotorax is not a reliable character to identify these species. As suggested by Ian, you should focus on legs and furcal branchs ornementation.
  • Megacyclops viridis : First article of P5 wider than long. Subapical spinula at second article not extended beyond the end of the article. Ti longer than the furcal branch. Last article of enp.P4 with 2 apical spines, shorter than the article.
  • Acanthocyclops robustus : First article of P5 as long as wide. Subapical spinula at second article extended beyond the end of the article. Ti shorter than the furcal branch. Last article of enp.P4 with 3 apical spines, shorter than the article.
Note that the taxonomy of Acanthocyclops robustus is not up to date in both Rybak & Bledzki 2005 and Einsle’s 1996 guides. Most of the time, specimens identified as A. robustus are in fact A. trajani.
See :
  • Mirabdullayev, I. M. & D. Defaye, 2002. On the taxonomy of Acanthocyclops robustus species complex (Copepoda, Cyclopidae). 1. Acanthocyclops robustus (G.O. Sars, 1863) and Acanthocyclops trajani n. sp., Selevinia 1-4: 7-19.
  • Mirabdullayev, I. M. & D. Defaye, 2004. On the taxonomy of the Acanthocyclops robustus species complex (Copepoda, Cyclopidae): Acanthocyclops brevispinosus and A. einslei sp. n., Vestnik Zoologii 38: 27-37.
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This is from java brackish estuary.
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Sulistiyowati, I personally find it quite difficult identifying zooplankton from photographic images, my first impulse is to zoom in as one would on a good stereo zoom microscope, which is not always possible with low resolution photos.  The exception being of course when one views a familiar species, one that is easily distinguished from others in the sample.  To this end, let us hope there is someone out there that may recognise the specimens posted by Priscilia!
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Can someone tell me what are the methods used to determine Calanus finmarchicus age?
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Are you looking for  days after hatching?  I don't think there is a method to determine that.  However, you can stage the animals and if you know the average temperature you could estimate the "time post hatching"
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Does anybody know methods to measure mortality stoichiometric parameters in zooplankton in an RWQM1 model?
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Sorry. I am a marine biologist
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I need to find the main variables in the ecological and morphological phenotypes of marine zooplankton which define the trophic niche I order to build a comparative multivariate matrix.
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This nice paper will give you some quite relevant info.
How zooplankton feed: mechanisms, traits and trade-offs
Thomas Kiørboe
DOI: 10.1111/j.1469-185X.2010.00148.x
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I am looking for reliable datasource for various microzooplankton taxa. I am focused on North Baltic Sea microzooplankton but any other source would be welcome as well.
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Lennart, which zooplankton groups do you consider as microzooplankton (it differs)?
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Zooplankton behavior observation set-up. Do you know any references where those set-ups are described in details?
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Danny Grunbaum at the University of Washington had a 3D video setup and did some really neat modeling/observational work with plankton. His web page is at http://faculty.washington.edu/random/.
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We know from the manual that after getting the zooplankton samples from Net, It is needed to filter the samples to remove the salt by distilled water, However, there is no detail method to filter the samples for POC treatment. For example, what kind of seives or filters (GF/F) are used for filtering? what kind of cases were used to transfer these wet samples to oven for drying? How long it will take for the drying? What is the temperature we should keep?
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Hi
It is desirable that you use sieves of different mesh sizes in order to obtain a number of size-fractionated subsamples.
These articles may be of your help:
Best
Dola
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In your sequence data set, did you have any sequences (OTU) closed related to zooplankton?
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Hi there! Look I have the idea of studying lakes, different lakes with different environmental histories (natural + anthrop.), considering their pelagic biota an then studying the biota's responses(physiological to molecular and functional) under simulations of future enviromental conditions (°C, pH, etc). I think should be interesting to connect these observations with current and previous genetic diversity of lakes.
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I have 5 sampling sites (throughout the estuary, a small one), and a 8 yrs time-series.
My question concerns the effects of seasons vs year-to-year variability.
Can I apply a PCA in a matrix 8 yrs (annual average of the 5 sites) x 23 plankton indicators ( were selected based on functional groups, dominance of the taxa sampled, appearance of the seasonal peak, representativeness for each sampling site). For example :
Appendicularia summer
Chaetognatha aut
Nauplii cirripedia summer and spring
Nauplii cirripedia spring
Marine cladocerans autumn and summer
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Hi,
PCA is an option, for sure. However, it is often the case that there are a considerable amount of zeros in the data, which I guess is also the case with plankton where there is considerable variation in species competition within the season. This means that the ecological gradient of species occurrence is relatively long and under such circumstances PCA is not a good method for analysis (unless the data is transformed prior to analysis, see Legendre & Gallacher 2001 in Oecologia).
I would suggest that (given that your data is abundances and not presence/absence) that you first use some dissimilarity index to calculate the ecological resemblance between your samples (i.e., using vegdist in the vegan package in R). Then you can use Non-metric Multidimensional Scaling to gain a graphical representation of the original ecological space in, say 2-dimensions. This can be done using the monoMDS function in the vegan package in R.
I hope this helps.