diatoms, diatoms

Rene · Mai 10, 2017, 19:34:06 NACHMITTAGS

Got a nice fresh sample in from Antwerpen harbour. Who wants to take a guess? There's a free diatom slide waiting for the first who gets it right!

Best wishes, René

10x/0.4

20x/0.7

Bob · Mai 10, 2017, 19:42:14 NACHMITTAGS

Hallo Rene,

ich würde sagen Stictodiscus.

Richtig?

Viele Grüße,

Bob

Rene · Mai 10, 2017, 19:54:54 NACHMITTAGS

Leider Bob, nein. Try again!

TSchöll · Mai 10, 2017, 20:19:01 NACHMITTAGS

Hallo Rene,
könnte es Stephanodiscus astraea sein?
Gruß
Till

Rene · Mai 10, 2017, 20:33:18 NACHMITTAGS

Auch nicht Till...
Tip: forget the Kiefern pollen!

Here's another crop with the essential details:

20x/0.7

Best wishes, René

martin_hu · Mai 10, 2017, 20:34:30 NACHMITTAGS

Hi Rene

Aulacodiscus .....kittonii ....ev. crux

kind Regards

Martin

Rene · Mai 10, 2017, 20:46:23 NACHMITTAGS

It's the right environment, Martin.

Getting closer!

TSchöll · Mai 10, 2017, 22:28:42 NACHMITTAGS

Hallo Rene, noch ein Versuch. Last try. Is it Thalassiosira punctigera?

Rene · Mai 11, 2017, 08:17:48 VORMITTAG

Leider auch nicht Till, T. punctigera is much finer areolated, with a completely flat valvar surface. Also, the Prozessen on this diatom are different and very unusual!

Best wishes, René

ruhop · Mai 11, 2017, 08:33:07 VORMITTAG

Hallo, Rene.

Maybe the genus Coscinodiscus?

Greetings

Holger

Rene · Mai 11, 2017, 09:41:10 VORMITTAG

Weiter, Holger?

anne · Mai 11, 2017, 09:54:26 VORMITTAG

Hi René,

Coscinodiscus radiatus oder Coscinodiscus granii?

lg
anne

Päule Heck · Mai 11, 2017, 10:09:51 VORMITTAG

Hi Rene,
ich denke, Anne liegt richtig mit Coscinodiscus radiatus.
LG
Päule

martin_hu · Mai 11, 2017, 10:24:58 VORMITTAG

Coscinodiscus jonesianus var. commutatus

Martin

Rene · Mai 11, 2017, 11:34:27 VORMITTAG

And we have a winner! Coscinodiscus jonesianus var. commutatus, http://bibdigital.rjb.csic.es/ing/Libro.php?Libro=1006&Pagina=452, nowadays renamed Coscinodiscopsis commutata, due to the two strange processes on the edge of the valve.

20x/0.7, cleaned diatoms

I guess Martin has earned himself a diatom slide from this massive bloom in the brackish harbour of Antwerp.

Now, in pre-Hustedt era it was known as a variety of C. radiatus , so Anne and Paule could have been quoting from even older books. But without the mentioning of the variety Jonesianus, I cannot agree with it. The true C. radiatus is flat as a pancake (no stacking necessary, even with oil!) and, when alive, thin as a coin. That's a feature seldom seen by diatomists, with the old adagium: acid first, look later

. Coscinodiscus granii is more like it, but has in girdle view a very characteristic asymmetric shape. And of course, they both lack the two very typical processes, of which the function is still unknown!

Martin, if you send me a PN, I'l send you your slide. Anybody else interested, I have slides to trade/exchange!

Best wishes, René