Questions related to Freshwater Biology
The past few years have seen a lot of new cyanobacterial taxa being described using a polyphasic approach. It will be interesting to know that what are the various good things about using this approach and importantly, are there some particular taxonomic groups/clusters that are still unresolved where the polyphasic approach is still to give any proper answer?
What further developments do we anticipate in the coming years? What are the new techniques/methods that can be further incorporated for a better understanding of cyanobacterial taxonomy?
Are there particular impacts on aquaculture?
Also, how does the increase in zooplankton abundance correlate with fish population? Is it also somehow related to the effects of eutrophication?
Will highly appreciate your response on this matter. Thank you so much and have a great day!
How do you do to design an assay with primers and probes that function well and what program/platform do you use?
I'm using AlleleID now but I wanna try any other ways to design it.
I am currently planning to work on the Study of breeding biology of Glossogobius guris (Freshwater Goby) in particular reservoir (Rajdhala Beel, NetraKona) in Bangladesh for my MS thesis. I am interested to know how this study of breeding biology of Freshwater Goby in this reservoir can have socio-economic contribution. I will determine the GSI, Fecundity and Gonadal Histology, sex ratios, etc. of the particular population from the samples . Some past studies demonstrated that this species has good abundance in the reservoir. But no one worked on the breeding biology of this species in this area. How I can explain the socio-economic contributions of this study? I have already made some points of myself but additionally I need some strong points from the experts to make the objectives of the study more acceptable and more convenient in terms of benefit of people and the fisheries sector. Thanks in advanced for any kind of response anyone might provide.
I'm thinking of purchasing one and am interested to hear others experiences, especially problems they may have encountered.
My name is Hairul from Selangor, Malaysia, 36 years old, 175cm, 66kg. I am looking for an opportunity to further study in PhD level. Any body here looking for a PhD student in research field such as wildlife management, conservation biology or life sciences. So far my expertise on breeding assessment, exitu management, terrapins/turtles, ecology and conservation.
I'm very interested to obtain information about current state and further development of freshwater aquaculture (trends, topics, main problems, etc.). I will be very thankful for any ideas concerning this topic.
Can anybody help me with this freshwater snail? It was collected on 25.ix.2018 in a Ditch at Papenveer, The Netherlands by Nick Kroese (lat 52.186 lon 4.722) In The Netherlands we only have Physella acuta (=heterostropha) but this one is untypical. There is a garden centre nearby, so maybe a non-indigenous one? Any suggestions? It is photographed on frogbit Hydrocharis morsus-ranae.
Many thanks in advance
Ton van Haaren
I have a long term dataset which includes a variety of chemical and physical water variables sampled from an inland river. These variables include: metal loads (Al, Ca, Cd, Cu, Fe, Hg, Mg, Mn, Na, K, Pb, Ni, Zn); in Situ measurements (Electrical conductivity [EC], water temperature, air temperature, dissolved oxygen, pH); water nutrients (Ammonium, Chloride, Nitrate, Phosphate, Sulphate, Total Organic Carbon [TOC], Dissolved Organic Carbon [DOC]); and others (Acid capacity, base capacity). Some of these variables (e.g. chloride, EC, ammonium, nitrate, dissolved oxygen, phosphate, pH, sulphate, TOC and water temperature) were sampled consistently and therefore have a good resolution, whereas others (e.g. metal loads [Al, Cu, Fe, Hg, Pb, Ni, Zn], acid capacity and base capacity) were sampled less frequently and therefore do not have the same data resolution.
With that said, the focus of my research is not exactly the chemical interactions of DOC and other chemical constituents per se, but rather the interaction and effect of DOC on freshwater macroinvertebrate taxa. I do, however, understand that the interaction of DOC with other water chemical properties is of vital importance and ones needs to consider these interactions.
Therefore, I would like to know what variables (from the lists mentioned above) are the most likely to interact with DOC within the freshwater environment. This will aid in my selection of the relevant variables that I will carry into further statistical analyses.
Any help in this regard would be greatly appreciated.
I'm currently working on freshwater soil nematodes for my undergraduate thesis.
After sieving the soil to obtain nematodes, I've been having a hard time fishing them from the water/supernatant so that I can examine them on the compound microscope for identification. I have tried using a single "thread" of copper wire I got from our sound systems at home, but it seems too thick to fish out any nematodes. I've also tried using a micropipette, but it's very difficult to handle. Is there anything else you could suggest I use to fish these nematodes out from the water? Or is my method itself wrong?
Thank you so much!
The lake is c.6.3 hectares and <1m deep. The lake has slightly elevated TP and TN concentrations and there is a concern that removing the invasive water soldier could cause a phase shift from a clear macrophyte dominated state to one that is turbid and phytoplankton dominated. Any comments or experiences about how to approach the issue are welcome. Also how realistic is it to fully remove water soldier so that it does not return?
I have a dataset of fish collected in different rivers over different years each of them sampled a different number of times during different projects . This different number of observations among rivers in some cases can be important: e.g.
River X = 1 project (1 observation=1 sampling x 1 year);
River Y = 5 projects (15 observations= 1 sampling x 3 years x 5 projects);
River Z= 15 projects (105 observations=1 sampling x 7 years x 15 projects);
I want to calculate in the all region (so not interested in specific rivers) how the abundance is related to Years, Latitude, Altitude and Anthopic pressures (APindex). I thought to use the following model:
lme: Abu~Years+Latitude+Altitude+APindex + (1|river/project) + corrARMA (form = time|River/project).
-What is the influence of RiverZ with its 105 observation compared to the other rivers which have less number of observations?
-Am I accounting for this unbalanced observations in the random structure (1|river/project)?
-Do I have to account in the model for the different number of observations with (weight=1/n observation for each project?)
I am looking for an identification manual that can be downloaded for a project regarding an inventory of freshwater gastropods.. any help is greatly appreciated...
What could be the reason of a massive single-night macroinvertebrate drifting event occurred in an sub-alpine stream after 2 days of a 4 week experiment performed in Mai 2014? Drifting rate of the night before and of the night after was 100 times lower then the one observed during the night of "the event". Moon-light intensitites? Ice melting? Thanks in advance
I am attempting to grow a strain of Synechocystis, that was originally grown in enriched seawater media, using BG-11 media. They are being grown at 25C on a shaker under about average room lighting (as suggested). The only thing have changed is the media. I am seeing growth and am able to keep living cultures but they are not as "vibrant" as I was hoping to be able to produce. Is there anything I can try to keep them stable in this media before moving to enriched seawater media?
I am looking for help with a presentation I am doing for my Microbiology class. I am doing a research presentation on tardigrades (aka water bears or moss piglets). As part of this project, I decided to "hunt" for some tardigrades of my own and successfully found some in a Spanish moss sample collected nearby a local lake. In the sample, I noticed several cells that appear to be peritrichous with an "x" shape in what appears to be a nucleus. The tardigrades appeared to gather around these cells and even possibly cling to them. I was wondering if anyone could give me some ideas as to what they could be so I could do some further research and maybe describe a possible relationship between the tardigrades and these cells. For some reference, this was viewed under a compound light microscope with a 40x ocular lens, for a combined magnification power of 400x. These cells appeared to be over double the size of the tardigrades and were stagnant. Any help is greatly appreciated. You can see the "cell" pictured her. It is hard to make out, as there is algae gathered around it. I also keep calling this a cell, but given it's size, I'm not sure if it's single-called, or a multicellular organism. Thank you.
A co-worker found this unknow flatworm along a citycanal in Amsterdam. We have no idea what this might be, so any help is welcome. It is probably non-indigenous. It was collected using a pondnet in the canal, but it may prove not to be aquatic after all.
We are pleased to invite you to the 5th meeting of Fresh Blood for Fresh Water. The meeting will be held this April in Ceske Budejovice, Czech Republic. The idea is to connect young students (bachelor, master and PhD) and early career scientists from all around the world.
Present your work, exchange ideas, start new projects and collaborations with a glass of beer in a relaxed atmosphere. Details are available on the website:
Abstract submission will be CLOSED on 20th of February! Find all necessary information on how to apply:
Check our key note speakers:
Please send your abstracts and related questions by e-mail:
We look forward to seeing you in April!
Organizing committee of FBFW
The pictures below are 400X magnification of lake water sample taking in winter in Quebec, Canada. On the scale, each line is 2 um. The 3 first pictures are different views of the same organism and the 2 pictures fallowing are different views of the same organism.
Are Atlantic sturgeon known to enter the tributaries of the rivers they use? I imagine these tributaries might be too shallow for spawning, but do juveniles utilize these areas?
My feeling is that the amount of decomposition attributable to shredders is less in lentic habitats, but I don't have much supporting evidence.
When sampling freshwater sediments (with corers and dredges), we will occasionally pull up sediments that are more water than sediments for the very top 5 cm or so. This top layer is easily poured, thicker than milk but thinner than a good thick milkshake. In limited experience, this tends to happen in ponds that are isolated from flows and wind. Since the firmer sediments are now several cm below this layer and, the thin and underlying thicker sediments layers tend to be black and probably low in oxygen, I am wondering what, if anything, could be living here. Anyone familiar with these sediments?
Please find the attachments of full view and dissected parts of cyclopoida.
I have got one diatom for identification for my colleague. but I could find it. please any one identify it. freshwater form..please help me in this regard..
We are experiencing high mortality with our Galaxids die at around the 14th day after hatching. I thought it could be that they are not able to inflate their swim bladder. In the wild they spawn at sea/brackish water and at around week 12 they migrate to freshwater. Does anybody know what sign to look at or if there is another reason. The lab didn't show any pathogen and said most fish had empty guts. I think due to their inability to swim properly made them not able to catch the live food we offer.
Working on the ecology of streams and the effects of land use changes on aquatic biodiversity
A microfilaria -like larva was detected by one of my student in a monogenean worm. Have you heard of a similar observation published in this field.?
but it is better ,if i can use universal indices and indices that can be use to south Asian region as well.In addition indices should be included to cover species richness,species evenness,species heterogenity (3 aspects of Species diversity)
See the attached files. Zooplankton was collected in a large reservoir in Ukraine. Length approx. 0.2-0.3 mm.
As the question states I am looking for papers detailing the impacts of recreational boat traffic on benthic macroinvertebrate assemblages. Much of the research material I have found thus far is focused on marine and brackish waters. Are there any papers available specialising within lentic freshwater environments?
I need to collect a maximum of information on projects dealing with reduction of silver eel mortality at hydroelectric facilities by the method of catch & transport. All information collected will be shared with all contributors afterwards.
Thanks to contact me in private if you are interested.
Mostly biotic indices I have found all based on lotic ecosystems. Only Nepal lake biotic index (NLBI) is the only index I came across that can be used in lentic ecosystems.
It is a freshwater copepod, this seen in the microscope in 4X. measuring about 2 mm.
Images are ALIMVI laboratory, of the Department of Aquaculture the University of Córdoba. Colombia
Aprecio su opinión.
We tried many unsuccessful techniques to remove alien pumbkinseed fishes from our places. Maybe wrongly, we used net, electrical fishing, hooks. The only success was the heavy technique of drying a water pool. Use of piscicide may be a problem on a protected place, but please share your expertises and good idea. This sunfish threaten many rare amphibian larvaes and invertebrates .
They live in Rainbow Springs State Park and Reserve in Dunnellon, Florida. Their habitat is clear fresh water. The fish I saw was staring at the bottom of the spring at 45 degree angle, probably waiting for some larvae to come out. What could they be eating. They especially frequented the bubbling silt of the spring, again, staring at it.
The present study should take place in a subtidal environment with rather large current speeds and waves action. The question is mainly about the exchange rates between the interstitial water and the water column that might decrease the retention of the local DNA rich extracellular products and increase the import of products from elsewhere... In advance than you for your answer! Kind regards, Vincent
Quantitative and qualitative assay methods for xenobiotic pesticides persistent in fresh water lakes surrounded by several flower farms that uses pesticides and fertilizers that leaches into the lake.
My partner and i are trying to study the foraging behavior of Hydrophis semperi, a freshwater sea snake. Not much is known about it so we're just basing our study on the foraging behavior of other snakes. We are planning to use search and handling time as a factor. Other than that, we only have descriptive data. Are there other aspects we can quantify?
There are a large number of samples to test and the study site is a significant distance from labs.
Standing water bodies like ditches, canals and (small) lakes that are shallow (< 1 meter) can have a bad ecological water quality with high nutrient concentrations and algal blooms. I am looking for studies that describe the relationship between water depth and water quality and possibly also the underlying processes. Any suggestions?
Edit: I would like to emphasize that i am looking only for scientific or 'gray' papers that i can use as a reference for the relation between water depth and water quality. I am currently not looking for research suggestions or sampling protocols.
I am working with Daphnia magna and meet serious problems:
1/ 24 hours after feeding, medium started to be oily and have opaque light green (fig 2).
(3 months ago, I fed the same concentration of food (Chlorella vulgaris and YTC) but medium have very clean light green color after feeding 24 hours).
Concentration of food can be clearly observed in fig 1.
2/ Daphnia suddenly have smaller size than before although feeding is same.
3/ Daphnia have many eggs (brown eggs) but they stay long time in brood chamber until turn into "white eggs" (white color) (fig 3) and broken (death). So they can not hatch into babies.
Maybe it's caused by brood parasites? How can we solve this problem?
I am very thanksful for your help.
See dropbox link to video of thousands of goldfish (wild Carassius auratus) in the outlet of a lake. Madness!
Images courtesy of Matt Brady from Hawke's Bay Dept. of Conservation.
Any thoughts on what is going on would be much appreciated. Anyone seen this before?
Their gonads do not appear to be overly ripe. Certainly not running ripe.
This is the outlet to a shallow eutrophic lake (<2m deep). -39.574925, 176.761165
Speaking to some NZ scientists, our best guess is conditions became unsuitable in the lake and flushed fish are recovering in outlet. There was a recent cyanbacteria bloom, though toxins were not detected. Temperatures have dropped going into winter. Algae and macrophytes likely dying back. From helicopter, fish appear to have congregated in clearer flowing section of stream.
Have you seen similar congregations?
Any ideas/explanations welcome.
When undertaking some chironomid exuviae work on a lake choked with water soldier, some of their leaves were found with rows of some form of seeds growing through them (see attached photos). I know it might be difficult to establish exactly what it is, but their elegant positioning in rows caught the eye. Incidentally, I have also attached a photo showing the choked lake for context. I have previously asked a question about people's experience of removing it.