Hello,
the technic Chris describes is undoubtly the one which is to be used for most people interested to look for those conidia.
All other techics require equipement or laboratory which is not available to most people or are costy.
As I have the opportunity to participate on a project on fresh water fungi in the National Park Bavarian Forest, I had the possibility to buy a filtering system to filter the conidia out of the water and so I'm not rstricted to foam respectively to locations where there is foam. By filtering rivulet water we have the chance there to investigate definite long-time plots which are investigated by other researchers too and also we can repeat the same treatments very year.
For this purpose I have a filtering system as said, which presses the collected water through a very fine-pored filter by an underpressure of appr. 5 bar (more pressure could result in breaking the arms of the conidia)
The attachment Bild1.jpg is no longer available
In the place where the blue clamp connects the two bottles parts, a ceramic filter with a pore size of 5-8 µm and a round filter paper with square grid is located. To press through one liter of water it needs approx. 20-30 minutes when you keep up the pressure at 3-5 bar all the time.
After that you loose the clamp and take out the filter paper and store it in a round petri dish in which some drops of cotton blue in lactic acid have been given. The lactic acid works as a fixative and the cotton blue stain the conidia at the same time. You can keep that filter in the dish for month as the lactic acid while not dry out
The attachment Bild2.jpg is no longer available
When you try that method, we have found that it is important to let the collected water stand for some hours (at least two), so that the particles floating in the water can settle on the bottle ground. When you then shake the bottle gently a bit and let it stand again for 15 minutes, you will have the conidia still floating around but have the particles sedimented, so that your paper filter is not full of dirt and mud. The above picture shows my first attempt two years ago in which I did filter the water directly from the rivulet without letting it rest for some hours ....
The filter then can be cut in half an be placed on a slide and covered by a big sized cover glass. The square grid on the filter allows you to statistically count the numer of conidia in a certain amount of squares.
The attachment Bild3.jpg is no longer available
some examples of those conidia
There are still other ways of fishing conidia, and there are usefull books which give ideas on what you could do.
In the said project in the National Park Bavarian Forest we resticted for the moment on doing the investigation of leaf litter and twigs by molecular purpose and additionally search in the same 15 long-term plots for teleomorphs on the (partly or completely) immersed woody substrate. This looks like that:
The attachment 20170607_094349.jpg is no longer available
The attachment 20170606_103056.jpg is no longer available
The attachment 20170607_095914.jpg is no longer available
a collecting box, in which we can transport the collected submerse fungi under water and we can even send them like this by parcel service to the laboratory taking cultures of them
The attachment 20170608_121528.jpg is no longer available
best regards,
Andreas
). Other suppliers and similar containers are doubtless available. This speeded up the process considerably and made breaking down the foam easier. Adding a few drops (usually no more than half a dozen) of fixative to the foam needs to be done at the same time as the collection - otherwise the minute the conidia touch a solid object they will start to germinate. This process tends to complete the breaking down of the foam quite rapidly. Seal your container and there you are.