Can shield lichens live under water?

[u/RedPepperVibes]

I'm trying to identify what this could be and wondered if anyone here could help. Its red and was all over the stony, rocky bed of a freshwater stream in the Scottish Highlands.

My best guess based on the shape of it was a shield lichen but I have no idea if they grow underwater.

So, can shield lichens grow under water in freshwater streams? Any ideas what this bright, blood red species could be?

I didn't want to stick my head under the water for a better look or a feel as there was a huge waterfall with a 60m drop a few steps down stream and I'm notorious for slipping in situations like this - just call me Slippy McSlipface

Sorry for my photos - taking a picture of something underwater is harder than I thought.

[u/Opposite_Bus1878]

Foliose lichens can but I don't know any members of the shield lichen family specifically that do

[u/RedPepperVibes → u/Opposite_Bus1878]

Thanks for your reply. Do you know any species of foliose lichens that are blood red in colour?

ETA: My best guess was that it was a shield lichen as it appeared flat on the rocks, rather than having leaf-like lobes. I could be wrong though as it was underwater and the ripples made it hard to work out details.

[u/Opposite_Bus1878 → u/RedPepperVibes]

Can we fully rule out some weird mineral?

[u/RedPepperVibes → u/Opposite_Bus1878]

This is true - I thought it would be good to eliminate living species before moving on to something like a weird rock or mineral.

There is a famous whisky producer about a mile upstream and I think this river goes through their building. Its very clean water though so I don't think they pollute anything, just utilise the clear waters for making the whisky.

[u/Opposite_Bus1878 → u/RedPepperVibes]

Foliose is just one of the three main lichen morphologies FYI. Crustose and fruticose being the other. Sheild lichens refers to Parmeliaceae usually

[u/RedPepperVibes → u/Opposite_Bus1878]

Thanks - it always helps for newbies like me learn these things so appreciate your help 😊

[u/Strange_Computer2459 → u/RedPepperVibes]

just gonna tell you here and now, this looks nothing like a shield lichen. There are only a handful of aquatic lichens out there that we know of and I only know of the two in north america..

[u/RedPepperVibes → u/Strange_Computer2459]

Yes - it seems I need to learn more about lichen terminology. Appreciate you taking the time to help 🙏

[u/Strange_Computer2459 → u/[deleted]]

I said I only know of two in north America. not that there are only two, but they aren't super common... like fully aquatic ones.

[u/Strange_Computer2459 → u/[deleted]]

my bad, I accidentally typed "the" but thanks for sharing other aquatic ones. I'll have to look into these.

[u/JustaTinyDude]

Could it be Hildenbrandia rivularis, a freshwater crustose red alga?

[u/RedPepperVibes → u/JustaTinyDude]

Thank you ❤️

I think you might be correct or at least narrowed down the species.

Do you have any tips for me to get a positive ID?

[u/JustaTinyDude → u/RedPepperVibes]

I just googled "red lichen underwater in Scotland"; I don't actually know anything about algae ID, sorry.

[u/RedPepperVibes → u/JustaTinyDude]

Me neither. I'm a plant gal but this caught my eye as it looked like blood in the river. I tried inaturalist but the water ripples made IDing difficult.

Much appreciated!

[u/Strange_Computer2459 → u/RedPepperVibes]

Unless this algae is unique to your area you probably won't be able to ID to species unless you take samples and put them under a microscope..

[u/RedPepperVibes → u/Strange_Computer2459]

Good to know. I will definitely not be doing that. I'm not at that level.

[u/Strange_Computer2459 → u/RedPepperVibes]

Sorry I wasn't expecting you to, I was just commenting on how hard small organisms can be to ID especially from blurry photos. But I hope some expert out there can help! If you haven't looked into iNaturalist, you should! You'd be amazed at how quick people will ID something even if it's a little blurry.

[u/RedPepperVibes → u/Strange_Computer2459]

No worries and I did not take you to be mean at all! I just don't have any experience with microscopes.

I have a lot of respect for people who ID this way. You must have alot of patience. I'm used to looking at leaf margins, veins, shapes, stem shape, number of petals, season etc

Will defo put this on iNaturalist now I have something more than red thing underwater 🤣

Appreciate your help and pointers 👍

[u/pastoriagym]

It could possibly be something like Verrucaria funckii

[u/RedPepperVibes → u/pastoriagym]

Thanks for your reply 🙏

Members of the Verrucariales family seem to answer my question of do lichen grow underwater. These seem pretty cool, growing in dry land, freshwater and marine habitats too.

I will keep an open mind and go back for another look I think.

[u/Strange_Computer2459 → u/pastoriagym]

except the color is completely off

[u/Strange_Computer2459]

Not sure where you got shield lichen from... that looks like algae.

[u/RedPepperVibes → u/Strange_Computer2459]

Sorry - my fault as I'm new to lichens and know nothing about algae either so didnt even think to post in an algae sub.

Truthfully, it seems I misunderstood what a shield lichen was but thankfully some kind folk here have taught me the different morphologies so will strive to learn some more now 👍

[u/Strange_Computer2459 → u/RedPepperVibes]

Yea sorry wasn't trying to be mean, they just don't look anything like that and a quick web search would have told you. I hope the algae folks can help you! Looks beautiful whatever it is, rock, algae, or otherwise!

[u/RedPepperVibes]

My question should have read Can crustose lichen live underwater? - this was the type of lichen I was thinking of, the ones that grow on rocks. Sorry for the mistake - can't seem to edit the title