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UltravioletPhotography

UV reflectance of fungi/mushrooms?


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FungiAreFun

Hi All,

 

I am a fungal ecologist in Sweden and have recently been analysing the colour variation in some of the fungi fruit bodies. This got me to wondering about UV reflectance in fungi and whether it would be worth following up as an avenue of research. For instance, do fungi which we think are likely dispersed by insects, but are quite inconspicuous in colour/smell have some sort of UV pattern that insects can see (similar to some flowers)? I know from other photos on this forum that fungi do light up quite spectacularly with UVIVF photography, but I am interested in just the UV reflectance for the purposes of my research.

 

Before I either spend my own money or get research funds to buy the equipment to measure properly though, it would be fantastic if I could get some idea of whether there is likely to be any sort of UV reflectance from fungi. This is especially the case if I am going to make the argument to get research funds to buy equipment. So I was wondering if anyone here might have some UV reflectance photos of fungi that I could just have a look at? I wouldn't need to use these for research itself, just to give me an idea of what is possible.

 

Thanks, Sam

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I only have two myself. The first one, an Elegant Stinkhorn (quite a spectacular thing!!) is posted here: Mutinus elegans [Elegant Stinkhorn]

The Stinkhorn shows some absorbing and reflecting areas in UV - dark on the end and bright on the stalk.

 

I also have a little mushroom which I'll go dig out and post.

 

EDIT LATER: Turns out I found a third example. Also posted below.

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And here is the little fellow -- which does have an interesting UV-dark (absorbing) stalk with a brighter cap. As it is my only other example I don't know if the UV-dark stalk is common. These photos were made with my old D200, thus they are not the best, very noisy. But you can still easily see the dark/light areas.

 

Visible

fungus_vis_sun_20070630wf_15258pf.jpg

 

 

UV using UV-Nikkor 105/4.5 and BaaderU UV-pass filter in sunlight.

fungus_uvBaader_sun_20070630wf_15259pn.jpg

 

 

Things to look for, perhaps, are whether the mushroom cap stands out against the grass in UV, or against a bark background or against soil. For example: we have found some UV-dark floral signatures which stand out against a UV-bright desert floor. So "patterning", per se, is not always there in a UV-signature yet the plant seems to have evolved a way to call attention to itself. (I'm merely speculating as I'm only an amateur botanist.)

 

I don't know anything about the pollinators of fungi. I've seen flies and beetles and other bugs on them. It would be worth checking into which of these pollinators have UV vision. Flies could see the tops of fungi growing in grass so perhaps might fly-see a UV pattern? Smell must be a powerful signal to pollinators because that Stinkhorn is named that for a reason. My goodness, that thing was smelly.

It's probably true that some fungi have evolved multiple pollination strategies just as have some flowers. "-) It would be very interesting to learn whether UV-signatures play a role.

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aha! I found another one stashed away under the folder name "mushroom" rather than "fungus".

 

Not much going on with this one, although that too tells us something. :)

 

Visible

mushroom_vis_sun_20151102wf_41573pn.jpgmushroom_vis_flash_20151102wf_41665pn.jpg

 

UV

This one does not have a UV-dark stalk. The gills are somewhat more UV-absorbing than the cap or stalk. But several photographs should be made of the gills before any final conclusion on that. The angle of the illumination can sometimes play a role.

mushroom_uvBaader_sun_20151102wf_41575pn.jpgmushroom_uvBaader_sb14_20151102wf_41691pn.jpg

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Sam, have you run across anything at all in the existing literature regarding UV signaling in fungi? Of course investigating the negative - that there is no particular UV signaling in fungi - might not be a proposition which gets funded given the way scientific funding usually works.

 

I will try to be more active about photographing the fungi I run across. I seem to have paid too much attention to flowers at the expense of other interesting subjects like moss, fungi, or lichens.

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  • 2 weeks later...
FungiAreFun

Thanks everyone for the photos! Really nice to have some more to go on.

 

Andrea, I haven't come across anything in the literature about UV signaling in fungi, as far as I am aware, no one has really looked at it from a ecology perspective. There are papers on using UV light to kill fungal spores and some edible mushrooms exposed to UV have increased amounts of Vitamin D, but that is all I have found so far. Part of the reason I was so curious, because it seems like no one has really done anything on it yet - which is always exciting!

 

Oleksandr (a member here) and I went out yesterday and took some photos of my study species with his UV camera (a huge thanks again Oleksandr!). He is pretty busy for the next few weeks but has said he will upload the photos he took to this thread sometime in the next month. Of the three species we photographed, one doesn't seem to have any UV reflectance, but the other two appear to be reflecting some UV light on their spore producing surface, however there is no patterning or anything like you see flowers. Obviously it would need to be tested more, but perhaps this might make these spore surfaces more visible to insects that can see into the UV spectrum. Really great to have some photos of the species and a better idea of what might be happening.

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Andrea B.

Thank you for the update, Sam.

 

Sometime soon I should find some mushrooms here in my yard. So this year I will be sure to photograph them in UV.

 

I have been fascinated with the UV-induced fluorescence of some mushrooms shown in posts here on UVP. That might also be an interesting thing also for you to investigate?? And it does not require a converted camera. "-)

 

Does mushroom fluorescence have some evolutionary value to the fungi? It must else it would likely not be happening. Although I suppose one could make the argument that fluorescence is simply a by-product of some fungal chemical necessary to the mushroom for reasons other than fluorescence.

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Andy Perrin
Does mushroom fluorescence have some evolutionary value to the fungi? It must else it would likely not be happening. Although I suppose one could make the argument that fluorescence is simply a by-product of some fungal chemical necessary to the mushroom for reasons other than fluorescence.

That's poor logic. Plenty of things have no evolutionary value but cause no harm so they hang around. You have even pointed out one possible alternative. (It's certainly possible it does have some purpose, but evolution does not guarantee that everything must have a reason for existence.)

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FungiAreFun

We were discussing this very thing at work yesterday! From an ecological perspective, I can't see any advantage to fluorescence as, for it to be an advantage, there would have to be a natural source of UV light other than the sun. Which I don't think there is - but correct me if I am wrong. It certainly is interesting that the do fluoresce so spectacularly though, I think Andrea might have a point in that it could be a chemical by-product. Fungi produce a huge range of chemicals which a strongly situation/environment dependent, while we know some of these, a lot are unmeasured/unknown, so there may be specific ones that cause fluorescence, which is an aside to the actual role they are performing. Yet another thing that could be studied in the future!

 

Thanks for the suggestion of photographing fluorescence Andrea! I am just about to order a Convoy S2 with the Nichia light to play with this a bit when I am out camping in the summer :)

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Another small thought: The reason we photograph UV-induced visible emissions in the dark (with appropriate filtration) is to isolate the visible emissions we want to record from any visible reflections. But that does not mean that UV-induced fluorescence cannot play a role outdoors in the sunlight. UV-induced visible fluor could possibly intensify already existing visible color reflection in the same wavelengths? Or possibly alter perception of already existing visible color in other wavelengths? I've never looked for studies which support any of this, but that's because I have so many other things to attend to!

 

So how would we show this? Not sure. Perhaps make a visible photo under full-spectrum UV+Visible sunlight with UV/IR-Cut filter on the lens. Then make a visible photo with visible light only (indoors? in the dark?) with UV/IR-Cut filter on both the illumination source and on the lens. I'm just not sure what illumination source one would use for the 2nd photo that would be broad enough?

 

Take chlorophyll in green plants. That produces UVI visible red. Outdoors in the full spectrum sunlight we do not have a perception of seeing anything but reflected green. But what would a more carefully controlled visible-illumination-only show for the reflected green? Would it be a "less intense" green? Or darker green?

 

You would need a good white standard which does not alter reflectivity under any kind of UV/Vis mix.

 

I wonder if I have made any errors in that little ramble??!!

 

BTW, my personal bias is that nothing occurs in nature without a evolutionary reason. But I am often cautioned that something could be a "byproduct" of something else. So I don't want to be too hard-nosed about it all.

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  • 3 weeks later...

Oleksandr (a member here) and I went out yesterday and took some photos of my study species with his UV camera (a huge thanks again Oleksandr!). He is pretty busy for the next few weeks but has said he will upload the photos he took to this thread sometime in the next month. Of the three species we photographed, one doesn't seem to have any UV reflectance, but the other two appear to be reflecting some UV light on their spore producing surface, however there is no patterning or anything like you see flowers. Obviously it would need to be tested more, but perhaps this might make these spore surfaces more visible to insects that can see into the UV spectrum. Really great to have some photos of the species and a better idea of what might be happening.

 

Here are the promised snapshots:

 

#1

 

post-29-0-71917600-1527359936.jpg

 

post-29-0-09006600-1527359944.jpg

 

#2

 

post-29-0-66575800-1527359952.jpg

 

post-29-0-90672800-1527359968.jpg

 

#3

 

post-29-0-27228700-1527359975.jpg

 

post-29-0-45844600-1527359984.jpg

 

/Alex

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  • 2 weeks later...
FungiAreFun

Thanks for taking and posting those Alex! It was a really huge help.

 

For those interested in the species they are:

#1 & 2: Daedalia quercina or Korkmussling

#3 & 4: I forgot my knife, so I couldn't get a big enought sample to ID properly, but some sort of Antrodia or Skeletocutis species

#5 & 6: Ganoderma applanatum or Platticka

 

Thanks again, Sam

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