Hello Gregor; You might look up some images of "bladderwort". From your photos I can't see much detail but the little blobs are inviting. Cheers, Jim Des Lauriers

The file I sent you can help. But I still recommend that you take a sample and examine it under a microscope.

Thanks a lot! Very valuable publication.

Regards

Gregor

Dear Gregor,

Not exactly an expert here and am only a palaeontology undergrad, but I've been keeping fish since I was 4 and have dealt with all sorts of microorganismal blooms and breakouts since. I have to say, this stumps me a little, I've not seen much like it personally, but my immediate thought would be cyanobacteria. The network does look like some species of nostocacean with regards to it's spherical components, but again, don't take my word for it. The PDF Hasan sent has a bit on 𝘕𝘰𝘴𝘵𝘰𝘤, and whilst I'm not sure your organism entirely fits the description 100%, it seems like it may be part of that ilk.

Many thanks and best of luck,

Edward

Perhaps: Nostoc pruniforme (Mare's eggs), a species of cyanobacterium?

I'm afraid 'nostacean' is about where I'm exhausting my level of discernment on this one. It seems similar to some of the photos of 𝘕𝘰𝘴𝘵𝘰𝘤 you can find on:

https://www.alamy.com/stock-photo/nostoc-algae.html

But, I cant provide much more specification beyond that. Sorry I can't be of more help.

Thanks for the pictures and comments. In a meantime I am quite convinced that the species is Nostoc pruniforme, forming such structures. The pictures I have posted were taken by my colleague next to Lausanne (Switzerland). It is a very rare phenomenon indicating water bodies with a high conservation potential for other aquatic organisms.

In the ices around the N Pole diatoms inhabit ice, caves in it and surface bellow the ice.... Your materials are obviousely fresh-water..

Dear Gregor,

Sorry, it looks dissimilar with any Nostoc and Utricularia.

This net of folds and bubbles is formed from neuston film floating at the water surface and completely covering this puddle. Several groups of algae can be responsible for this pattern of this color, e.g. some Xanthophyceae, Chlorophyceae and even Euglenozoa. The color of this film is not so suitable for cyanobacteria, but it need to be checked with microscopy.

Anyway, this habit of water body indicates its highly eutrophic status and high content of biogens and probably labile organic matter.

The miscroscopy of this film is essential for further ID.

Best regards,

Roman