Alboran Sea Diatoms

Here you can discuss sample and specimen preparation issues.
Post Reply
Message
Author
Charles
Posts: 1400
Joined: Mon Mar 02, 2015 11:55 pm

Alboran Sea Diatoms

#1 Post by Charles » Sat Apr 03, 2021 1:59 pm

75RR (Glen) sent me some seaweed and sand samples from the shores of Southern Spain in the Mediterranean, around the Alboran sea. Here are some pictures of the sample after cleaning and sorting through about 50 strew slides to a keeper slide. Taken through a B&L SZ7 and Canon EOS:
Left half of diatoms with 1X setting on the SZ7
Diatoms Left.jpg
Diatoms Left.jpg (95.3 KiB) Viewed 1178 times
Right half
Diatoms Right.jpg
Diatoms Right.jpg (88.92 KiB) Viewed 1178 times
Close up of the different diatoms starting from the left at 7X setting on the SZ7
Spain Diatoms1.jpg
Spain Diatoms1.jpg (74.98 KiB) Viewed 1178 times
Spain Diatoms2.jpg
Spain Diatoms2.jpg (89.46 KiB) Viewed 1178 times
Spain Diatoms3.jpg
Spain Diatoms3.jpg (72.03 KiB) Viewed 1178 times

Charles
Posts: 1400
Joined: Mon Mar 02, 2015 11:55 pm

Re: Alboran Sea Diatoms

#2 Post by Charles » Sat Apr 03, 2021 2:01 pm

Spain Diatoms4.jpg
Spain Diatoms4.jpg (80.73 KiB) Viewed 1176 times
Spain Diatoms5.jpg
Spain Diatoms5.jpg (87.58 KiB) Viewed 1176 times
Spain Diatoms6.jpg
Spain Diatoms6.jpg (93.77 KiB) Viewed 1176 times
Spain Diatoms7.jpg
Spain Diatoms7.jpg (72.9 KiB) Viewed 1176 times
Spain Diatoms8.jpg
Spain Diatoms8.jpg (64.27 KiB) Viewed 1176 times

Charles
Posts: 1400
Joined: Mon Mar 02, 2015 11:55 pm

Re: Alboran Sea Diatoms

#3 Post by Charles » Sat Apr 03, 2021 2:03 pm

Some unusual (to me) diatoms
Spain Diatoms9.jpg
Spain Diatoms9.jpg (54.73 KiB) Viewed 1176 times

User avatar
75RR
Posts: 7813
Joined: Sun Oct 12, 2014 2:34 am
Location: Estepona, Spain

Re: Alboran Sea Diatoms

#4 Post by 75RR » Sat Apr 03, 2021 2:25 pm

Nice variety! - including a few I have not come across myself.

Thinking of following your example ...

When you mentioned that you 'swirl the water and then decant', is that by hand or with a centrifuge?
Zeiss Standard WL (somewhat fashion challenged) & Wild M8
Olympus E-P2 (Micro Four Thirds Camera)

Charles
Posts: 1400
Joined: Mon Mar 02, 2015 11:55 pm

Re: Alboran Sea Diatoms

#5 Post by Charles » Sat Apr 03, 2021 2:45 pm

I put the samples in a jar of water, swirl vigorously by hand and decant immediately to a second jar. I add more water to the sample jar again repeat until the swirled water is clear. Then I let the second jar settle for 24 hours, decant the top third of the water, add more water and decant again after 12-24 hrs until the salt water is gone.
Sample from Spain.jpg
Sample from Spain.jpg (125.59 KiB) Viewed 1167 times
Sample from Spain in Jars.jpg
Sample from Spain in Jars.jpg (104.66 KiB) Viewed 1167 times
After the salt is gone, I decant as much water off and add about 100 ml of HCl and let it set for a week. After a week, I decant the HCl off and put in fresh HCl for another week. Then I decant the HCl and add about 100 ml of H2SO4 and let set for a day. I then rinse with Distilled water, let set and decant at least 6 times until all the acid is gone. I try to remove any large particles of sand by swirling and decanting the top off. I then make strew slides of 12-15 drops on a slide warmed over a warmer. Then I pick off the diatoms to a keeper slide.

Of course you don't need to do the cleaning with the acids, but the sample will be full of organics and other minerals.
Last edited by Charles on Sat Apr 03, 2021 3:02 pm, edited 1 time in total.

Hobbyst46
Posts: 3416
Joined: Mon Aug 21, 2017 9:02 pm

Re: Alboran Sea Diatoms

#6 Post by Hobbyst46 » Sat Apr 03, 2021 3:02 pm

Fantastic diversity.
From which depth (in the mud, and below the water) was the sand collected ?
It is great that you do not boil in acid any more.
Zeiss Standard GFL+Canon EOS-M10, Olympus VMZ stereo

Charles
Posts: 1400
Joined: Mon Mar 02, 2015 11:55 pm

Re: Alboran Sea Diatoms

#7 Post by Charles » Sat Apr 03, 2021 3:04 pm

Hobbyst46 wrote:
Sat Apr 03, 2021 3:02 pm
Fantastic diversity.
From which depth (in the mud, and below the water) was the sand collected ?
It is great that you do not boil in acid any more.
I still acid treat, but just let the sample set in it and not boiled. See the edit above.

User avatar
75RR
Posts: 7813
Joined: Sun Oct 12, 2014 2:34 am
Location: Estepona, Spain

Re: Alboran Sea Diatoms

#8 Post by 75RR » Sat Apr 03, 2021 4:16 pm

Hobbyst46 wrote:
Sat Apr 03, 2021 3:02 pm
Fantastic diversity.
From which depth (in the mud, and below the water) was the sand collected ?
I used a jam jar to scoop the wet sand from the surface down to 2 - 3 cm at low water.

You might find this link useful. You can set it for your area

https://www.tidetime.org/europe/spain/estepona.htm
Zeiss Standard WL (somewhat fashion challenged) & Wild M8
Olympus E-P2 (Micro Four Thirds Camera)

Hobbyst46
Posts: 3416
Joined: Mon Aug 21, 2017 9:02 pm

Re: Alboran Sea Diatoms

#9 Post by Hobbyst46 » Sat Apr 03, 2021 5:03 pm

75RR wrote:
Sat Apr 03, 2021 4:16 pm
Hobbyst46 wrote:
Sat Apr 03, 2021 3:02 pm
Fantastic diversity.
From which depth (in the mud, and below the water) was the sand collected ?
I used a jam jar to scoop the wet sand from the surface down to 2 - 3 cm at low water.

You might find this link useful. You can set it for your area

https://www.tidetime.org/europe/spain/estepona.htm
Thanks 75RR. Local tide is just 10cm... :)
Zeiss Standard GFL+Canon EOS-M10, Olympus VMZ stereo

ScienceMatters
Posts: 81
Joined: Wed Dec 30, 2020 1:46 am

Re: Alboran Sea Diatoms

#10 Post by ScienceMatters » Sat Apr 03, 2021 6:07 pm

Jealous of your international sample! So many interesting and different species in there, and nicely showcased on the slide!

Charles
Posts: 1400
Joined: Mon Mar 02, 2015 11:55 pm

Re: Alboran Sea Diatoms

#11 Post by Charles » Sat Apr 03, 2021 9:53 pm

ScienceMatters wrote:
Sat Apr 03, 2021 6:07 pm
Jealous of your international sample! So many interesting and different species in there, and nicely showcased on the slide!
You will be surprised at the variety of different species from any location. Most locations will get you 25-40 species. The trick is:
- Getting a variety of samples...sand, plants growing in the water, rocks, or things in the water.
- A good quantity of the samples.
- Concentrating the diatoms
- Being able to manipulate from strew to a keeper slide to permanent slide, which shows you your different species.

You can see the variety I was getting locally from different locations as well as from other US locations in this post:
https://www.microbehunter.com/microscop ... =10&t=4227

ScienceMatters
Posts: 81
Joined: Wed Dec 30, 2020 1:46 am

Re: Alboran Sea Diatoms

#12 Post by ScienceMatters » Sat Apr 03, 2021 11:24 pm

Charles wrote:
Sat Apr 03, 2021 9:53 pm
You can see the variety I was getting locally from different locations as well as from other US locations in this post:
https://www.microbehunter.com/microscop ... =10&t=4227
Very interesting to read about your techniques and see the results. Without these methods I’d say I normally only see 8-10 species per slide.

Charles
Posts: 1400
Joined: Mon Mar 02, 2015 11:55 pm

Re: Alboran Sea Diatoms

#13 Post by Charles » Sat May 08, 2021 8:03 pm

I tried to make a test permanent side from this sample. I wanted to make a test slide because diatoms react different ways depending on their shape and side. I was trying to see if they would shift during the mounting process. I figured the most likely ones which would shift are the large ones like the Biddlulphia.

I cleaned a coverslip, applied some adhesive and put six samples of Biddulphia in different orientations, front, back, side, girdle attached and full frustule. I set the adhesive. Then I applied a drop of Zrax mountant and gently heated it and labelled it. And this is what I see.
Test slide.jpg
Test slide.jpg (90.52 KiB) Viewed 698 times
Like a bomb went off and crushed all the frustules.
Biddulphia.jpg
Biddulphia.jpg (49.87 KiB) Viewed 698 times
Now I'll see how I'm going to add some spacers to protect the diatoms.
Spacer discs along coverslip.jpg
Spacer discs along coverslip.jpg (37.91 KiB) Viewed 698 times

deBult
Posts: 200
Joined: Tue Jul 16, 2019 3:20 pm

Re: Alboran Sea Diatoms

#14 Post by deBult » Sun May 09, 2021 3:34 am

Would be interested to learn where you sourced the spacer discs please.

Best, deBult

Hobbyst46
Posts: 3416
Joined: Mon Aug 21, 2017 9:02 pm

Re: Alboran Sea Diatoms

#15 Post by Hobbyst46 » Sun May 09, 2021 6:45 am

Charles, I tried punching the spacers from an aluminum foil (as per your post), but it did not work for me.
MicroBob has suggested flat stainless shim rings. I bought some, 18x12x0.1 mm, to try. More for dry mounts, but maybe it will work with Pleurax as well.
Zeiss Standard GFL+Canon EOS-M10, Olympus VMZ stereo

Charles
Posts: 1400
Joined: Mon Mar 02, 2015 11:55 pm

Re: Alboran Sea Diatoms

#16 Post by Charles » Sun May 09, 2021 4:00 pm

deBult wrote:
Sun May 09, 2021 3:34 am
Would be interested to learn where you sourced the spacer discs please.
I take a hyperdermic need which has the beveled end clipped straight across and poke it into thin aluminum foil or disposable pie plates. You can see the description here: https://www.microbehunter.com/microscop ... &start=150

Charles
Posts: 1400
Joined: Mon Mar 02, 2015 11:55 pm

Re: Alboran Sea Diatoms

#17 Post by Charles » Sun May 09, 2021 4:03 pm

Hobbyst46 wrote:
Sun May 09, 2021 6:45 am
Charles, I tried punching the spacers from an aluminum foil (as per your post), but it did not work for me.
MicroBob has suggested flat stainless shim rings. I bought some, 18x12x0.1 mm, to try. More for dry mounts, but maybe it will work with Pleurax as well.
The only problem I see with rings are that when heated the mountant fumes need to escape from under the cover slip to the edges. The rings could prevent that and lift the slip up?

Hobbyst46
Posts: 3416
Joined: Mon Aug 21, 2017 9:02 pm

Re: Alboran Sea Diatoms

#18 Post by Hobbyst46 » Sun May 09, 2021 5:04 pm

Charles wrote:
Sun May 09, 2021 4:03 pm
Hobbyst46 wrote:
Sun May 09, 2021 6:45 am
Charles, I tried punching the spacers from an aluminum foil (as per your post), but it did not work for me.
MicroBob has suggested flat stainless shim rings. I bought some, 18x12x0.1 mm, to try. More for dry mounts, but maybe it will work with Pleurax as well.
The only problem I see with rings are that when heated the mountant fumes need to escape from under the cover slip to the edges. The rings could prevent that and lift the slip up?
Yes, likely. Will have to glue the ring with gelatin (or, better, PAM) first.
Zeiss Standard GFL+Canon EOS-M10, Olympus VMZ stereo

Charles
Posts: 1400
Joined: Mon Mar 02, 2015 11:55 pm

Re: Alboran Sea Diatoms

#19 Post by Charles » Sat May 15, 2021 5:18 pm

Test 2. I decided to try just adding a bit more mountant. Came out a little better but still some breakage, but it may have happened because the coverslip wasn't sitting right and I had to move it a couple mm. May also be the reason one of the Biddulphia moved. Taken with B&L SZ7 at 7 setting and Canon EOS.
Alboran Sea Test2.jpg
Alboran Sea Test2.jpg (60.61 KiB) Viewed 425 times

User avatar
75RR
Posts: 7813
Joined: Sun Oct 12, 2014 2:34 am
Location: Estepona, Spain

Re: Alboran Sea Diatoms

#20 Post by 75RR » Sun May 16, 2021 6:25 pm

Nice ... seems you are almost there - then again the Biddulphia have got to be some of the most challenging to mount!
Zeiss Standard WL (somewhat fashion challenged) & Wild M8
Olympus E-P2 (Micro Four Thirds Camera)

Post Reply