Pensacola Beach Florida Diatoms

[KurtM]

This is for Fan, and anyone else who might enjoy it. The Z family took a vacation to Pensacola Beach recently, and Fan was kind enough to bring back a big bunch of sand samples for me. Maybe some other people wouldn't be quite so thrilled to get a box of sand for a souvenir, but it thrilled me and my inner arenophile to no end. I'll be having fun with this material for a long long while to come - thanks again Fan!

So after digging out a bunch of forams, it was on to extracting whatever diatoms might be lurking in the sand. The process is taking a bit longer than anticipated, but I finally have a couple slides prepared, and more on the way. I won't say there are just tons of diatoms to be found, but what I am getting is great! This is from the Langdon submerged.

Here is a great Auliscus I haven't seen before, still working on a positive species. But at least I can give its genus, I have no idea what the other is just yet. The Auliscus was shot in DIC through the Zeiss 40x/.65 lens, and dark phase contrast through the AO 40x/.66, all single frames as this guy refuses to be stacked. The first and second images are from near the top and bottom focal planes. The third image is the same diatom, but mirror-reversed.

The UFO (unidentified frustule obviously) is through the Zeiss 40x/.65 DIC, and stacked somewhat haphazardly. Also taken pre-processing fresh from the rinse water, as the golden chloroplasts attest.

[McConkey]

Great images Kurt! I especially like the 3rd one! Awesome detail!

Is this just good old fashion sand from any regular beach that you are interested in? If that's the case I can scoot on down my local lake and collect some samples for you. Maybe you'll find something exotic from up here in the great white north!

[exmarine]

Hi Kurt,
Yes very good images but if my mind drops into action I do believe that the centric diatom is one of your faviourites, anyway great photos.
I must get down to some diatom work been busy with 'Pond Life and Pollen'.

[zzffnn]

Very nice images, Kurt. I am glad you enjoy it!

Was the diatom sample difficult or easy to clean, after you filter away the sand particles?

In my first and only screen, I saw a few of your "UFO" s, along with a few other small symmetrical slender forms. Did not see the Auliscus.

In my screen, once I filtered away true sands with a 500 micron filter, diatoms were all that I could find (there were minimal detritus or other organic stuffs).

Karl,

Those marine diatom samples were taken from the very top surface of surface sand. Langdon Beach of Pensacola is facing ocean surf side.

Exact sampling location and time was: 3PM, Aug 17, 2016;
Google Map (GPS) coordinates: 30.316695,-87.262465
Submerged sand, Langdon Beach, surf side

Strong ocean surf brings the lighter diatoms/sands closer to beach (leaving heavier minerals behind), and I scooped only the top layer of those sands. Then I did water-rocking and took, again, only the surface layer to pass through a 500 micron kitchen screen (300 micron would work better) to remove true sand particles.

In a lake, when/where there is no much strong surf (and probably less diatoms to start with), you may want to go deeper into water and collect golden brown surface "slime" attached to rocks, tree branches and vegetations. It won't hurt to examine lake beach sands, though you may want to screen them under scope before sending. Postage of big/heavy items between US and Canada is not cheap.

[rnabholz]

Great images Kurt.

I know this is one of your faves, and for good reason, it is really interesting.

Nice job to Fan too. Does he pay you per site collected, or per pound? ;^).

[zzffnn]

Great images Kurt.

I know this is one of your faves, and for good reason, it is really interesting.

Nice job to Fan too. Does he pay you per site collected, or per pound? ;^).

Kurt pays me with a few prepared slides. Kurt is a rich guy, but I doubt he wants to pay per pound. I collected around 20lbs of sand. My wife and kids collected another 20 lbs of shells (those hoarders even kept broken shells). Good thing that we drove, not flew.

I collected at 5 sites in Pensacola.

It might be worth it, if one pays per pound for that Langdon Beach sample , which weights less than 1.2 lbs in total. Wet surface sand was not easy to scoop up, as ocean wave often blew away my collection. I only collected top surface sand, because I assumed only that lighter layer would contain diatoms.

[KurtM]

Thanks for the comments guys! Karl, I will certainly take delight in any samples from wherever they may come from, and the further away the better! But I think Fan's comments are well worth taking into account. I would have thought shipping from Canada to US would be prohibitive, although I really have no direct knowledge.

Yes, Auliscus is one of my favorites, here's why: A friend had moved to Florida some years back, and soon as got settled into his new home in St James City mailed a package of sand samples back to me. At the time, I washed all such samples before examining under crossed polarizers to clean up the view. As I began washing the first of my new Florida samples, it occurred to me to wonder what, exactly, was I washing away? So I washed another sample and retained the rinse water, let it settle, then placed a drop of precipitate on a slide and had a look under the microscope. I expected this step to be a mere formality, to see nothing more than nondescript debris and detritus. But I was blown off my chair to find a whole world of beautiful marine diatoms, as I was already well along in my diatom obsession by then! Talk about a moment that will stick with you the rest of your life, this definitely was. I had never seen or heard of Auliscus before, and as they were among the more conspicuous and extravagantly ornamented, came to symbolize the whole wonderful discovery experience for me.

Besides that, like Epithemia and/or Rhopalodia, they're just plain difficult to get good images of.

[rabitt]

Amazing what can be found if one takes the time to look.
Diatoms are becoming of greater interest to me.
Thank you.

[gekko]

Great images, especially #1, 3, and 4.

[zzffnn]

Kurt,

I just want to show you results of my quick and dirty screen. The following quantity and types of diatoms came from 5 ml wet sand from Langdon Beach. I did 15 ml water rinse, 5 min gravity precipitation and 500 micron filtration (nothing else). There were around 10 types of diatoms and quite many foram-like shells. I saw a few Auliscus in this screen.

Please excuse the terrible image quality. It was imaged with my portable scope, thick/uneven water mount without cover slip (hence lots of spherical aberration and out-of-focus areas), DIY darkfield mask and 8x NA 0.20 objective (total magnification is around 80x on sensor). Just for record keeping to show what was there, not for photography.

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[zzffnn]

One more screen result image:

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[KurtM]

What are you talking about, those are great pics! I'm gonna have to talk to you some more about your screening technique, especially now that I got this brand new sieve set sitting here waiting to go for a test drive.

[zzffnn]

Kurt,

Here is my exact screening procedure:

1) in a 15 ml tube, add 5 ml of sand and 10 ml water.
2) put a 300-500 micron pore sieve over a bigger petri dish.

3) plug the 15 ml tube, invert it 10 times and immediately pour out its content, over sieve/petri dish, right after the 10th inversion.

4) most sand would be poured out, while some sand would remain in the tube. Add another 5 ml water, invert 5 times and pour out everything onto sieve.

5) immediately collect all water from petri dish and pour it into a clean 15 ml tube. Let tube sit for 5 minutes.

6) carefully remove ~10 ml water, from surface, using a ~3ml pipette. Then using a 1 ml research pipette, carefully remove another 3 ml of surface water.

7) let the tube sit for another 3 minutes.

8) place the tube containing ~2ml water close to strong light. Using a 200 microliter research pipette, take the bottom precipitate, but try to avoid big sand particles.

9) place onto flat bottom well slide and observe.

Since you have 15ml x 6 centrifuge, you can stop before step 6) and use centrifuge to remove excess water. You may leave much less water (for example, 300 microliter) for more concentrated diatom sample - as you can see, leaving diatoms in 2 ml water, like how I did it, made them too diluted.

You can add precipitate from step 8) into hydrogen peroxide and/or sulfuric acid for cleaning.

Each sample may be different. The Langdon Beach sand is quite clean and has minimal organic debris. If lots of organic debris is present, extra rinse and filtration may he needed.

Edit:

If diatoms are attached to tree bark or vegetation, you may want to firstly mince the bark or vegetation in water. Then shake that mince water hard to dissociate diatoms. Then filter and start from step 2).