Are these the most elegant spores in the UK?

[Chris Yeates]

hello all

there's so much stuff around after those rains - can't keep up; a couple of hours in the field and a week of evenings back at the microscope (especially once you start photographing stuff)

this one of my very favourite species and it's one of the very few asco's (or indeed basidio's) you can identify from just seeing the spores; outwardly the fungus looks like any other 'black dot' species - it occurs on still-attached, but dead twigs of holly, and is presumably a weak parasite:


but under the microscope one can see its remarkable, large and to my mind exceptionally beautiful spores:




here is an aberrant spore (inset) which has clearly not been on the diet . . .


this is Vialaea insculpta the specific name presumably meaning (appropriately) 'carved'; its taxonomic position is not yet worked out and there is only one other species currently placed in the genus - Vialaea minutella - which is a similar weak parasite on mangoes in Hawaii (I kid you not! )

it's the fifth time I have recorded it, and the knack I think is to collect thin dead attached twigs of holly overhanging streams, for that is when my hunting for it has been successful: there are fewer than 30 records on FRDBI, but it is clearly under-recorded

ordinarily I would have posted this under the 'micro-fungi' or 'pick up sticks' threads, but I thought it would be interesting for others to suggest their own 'attractive' spores (or other micro-structures)

cheers

Chris

[Farplace]

Absolutely beautiful! Im going to have to get myself a microscope.

[Lancashire Lad]

Very nice Chris - I'll have to keep my eyes peeled for that one.

The aberrant spore looks almost like some sort of planarian.

Regards,
Mike.

[fairplay]

I would guess their shape allows them to 'stack up' quite tightly in the ascus, thus allowing for more spores per ascus ?
Or do you think there is another reason for this shape ?

Neil.

[Chris Yeates]

Only among the fungi . . . . . . . . . .

In a strange stroke of serendipity, today while walking through one of the museums in which I work, I did a double-take when I spotted an item obviously left over from a recent holiday craft event for kids - it was an arty type of pipe-cleaner (few know it but Huddersfield is the major producer of pipe-cleaners in Europe - there - you've learned something today!)

in the light of my post above you can see why I got all excited (and my colleagues thought me even crazier than usual) - here are two views of said pipe-cleaner:


look at the top shot - this was how I first saw it (I wonder how many kid's use it to make a funny moustache?) - it's the dead spit of a Vialaea spore; the bottom shot - where I have twisted it into a sigmoid shape - is how a number of the spores look under the microscope, but of course being more 3-dimensional it is less easy to get a decent micro-shot of those so I have posted the moustache ones in preference . . . .

I have been musing rather a lot on what the advantages of this (almost) unique spore shape must be in the last couple of days . . . . still thinking but will post some of my thoughts to Neil's question tomorrow . . . . . that sigmoid shape might be a clue . . . . and the spores are septate . . .

Chris

[SheffieldLass]

Originally Posted by Chris Yeates

I have been musing rather a lot on what the advantages of this (almost) unique spore shape must be in the last couple of days . . . . still thinking but will post some of my thoughts to Neil's question tomorrow . . . . . that sigmoid shape might be a clue . . . . and the spores are septate . . .

Chris

The moustache shaped ones come back like boomerangs and find other twigs on the holly, the other ones head off on long journeys, spinning to keep airborne for as long as possible .....

[fairplay]

Originally Posted by SheffieldLass

The moustache shaped ones come back like boomerangs and find other twigs on the holly, the other ones head off on long journeys, spinning to keep airborne for as long as possible .....

Yeh, there's billions of them, I can see them all - that explains my blurred vision.

Neil.

[Beamish]

Hi (after some time...)

I regard these spores as beeing most beautiful, too! I will try to attache some of my find and also a picture of those deviant ones. My impression is as yours that the form will enable them to fly high and at a far distance. They even "fly" in the water on your slide.
By the way: Dr. Robert Shoemaker in Canada might be interested to recieve some specimens for sequencing. If you are ready for that please contact me for the address.

Cheers,

Martin

[Chris Yeates]

Originally Posted by Chris Yeates

. . . . .
I have been musing rather a lot on what the advantages of this (almost) unique spore shape must be in the last couple of days . . . . still thinking but will post some of my thoughts to Neil's question tomorrow . . . . . that sigmoid shape might be a clue . . . . and the spores are septate . . .
Chris

Well it's taken me a while musing on this (scarcely 'tomorrow') - Neil suggested:

Originally Posted by fairplay

I would guess their shape allows them to 'stack up' quite tightly in the ascus, thus allowing for more spores per ascus ?
Or do you think there is another reason for this shape ?
Neil.

It's a thought but they don't actually pack up particularly tightly in the ascus; nor have I seen any evidence that they fracture at that potentially vulnerable central septum (within the ascus or when ejected), either in my own collections or in illustrations of those of others; perhaps that fracture occurs later, upon germination . . . .

Originally Posted by SheffieldLass

The moustache shaped ones come back like boomerangs and find other twigs on the holly, the other ones head off on long journeys, spinning to keep airborne for as long as possible .....

Originally Posted by Beamish

Hi (after some time...)
I regard these spores as beeing most beautiful, too!. . . . My impression is as yours that the form will enable them to fly high and at a far distance. They even "fly" in the water on your slide.
By the way: Dr. Robert Shoemaker in Canada might be interested to recieve some specimens for sequencing. If you are ready for that please contact me for the address.
Cheers,
Martin

[my emphasis]

My theory was that, as when I have collected this fascinating fungus in the past it has almost always been on holly close to (indeed often overhanging) running water, and the three-dimensional S-shape often seen is a one frequently seen in what used to be called "aquatic hyphomycetes" . . . I'm not convinced that they are adapted for the air at all

I contacted Dr Jerry Cooper in New Zealand, mentioning my theory of possible water dispersal and part of his response is repeated here:
". . . .those Vialaea spores are the classic sigmoid shape of the Ingoldians and adapted for water dispersal . . . I recall there is some literature on why that sigmoid shape is adaptive – for both transportation and settlement in water. It wouldn’t be anything to do with air-dispersal, i.e. like a samara, 'cos the physics doesn't scale."

samaras are the "propeller" fruits of sycamores and other Acer species which superficially have a similar shape to some of those Vialaea spores - when Jerry says "the physics doesn't scale" (and he was once a professional physicist) he means that the spores in air would have completely different aerodynamics to the sycamore fruits - we often forget that the air fungal spores encounter is very different from ours: it's a lot thicker relatively speaking, with far more resistance - the propeller would be highly inefficient in air, whereas in running water the water does the hard work - as Martin so perceptively says they "fly in the water on your slide"; and the sigmoid shape of course increases potential surface contact for germination . . .

this is of course all conjecture - it would be fascinating if an anamorph turned up, and if the proper taxonomic position of the Vialaceae could be sorted

Chris

[Beamish]

Hi Chris,

my find wasn't close to any water at all, it is from the courtyard of my office and holly isn't a classic inhabitant of wetlands isn't it? As V.i. beeing an at least semi-xerotolerant species growing on still attached twigs, I don't belive in the aquatic theory at a first glance.
But, when you can make it in the air you can make it everywhere... ;-)

Cheers,

Martin