Coscinodiscus?

[Ernst Hippe]

Hallo Maritime,

im Norderney-Schlick fand ich diese Schale:



Stimmt der Name?

[rekuwi]

Lieber Ernst,

der Name stimmt. Es handelt sich wohl auch um diese KA. Ich fand sie im Buch Marine Phytoplankton mehrfach abgebildet. In meiner Probe sah ich auch einige dieser Ka, leider so im Detritus vergraben, die wollten nicht fotografiert werden. Einige Bruchstücke waren sehr groß. Ob das auch rezente Teile sind?

LiebeGrüße
Regi

[felix]

C. radiatus?  Cf.

http://www.smhi.se/oceanografi/oce_info_data/plankton_checklist/diatoms/coscinodiscus_radiatus.htm

-- AF

[Ernst Hippe]

Hallo Regi und Felix,

C. radiatus ist sicher richtig - vielen Dank!

[Rene]

Hallo Ernst, I'm not entirely sure. C radiatus is entirely flat, really coin like. Have you stacked this one? Is it more donut-like by any chance?

The images in Marine Phytoplankton are not very typical for the entity that we generally regard as C radiatus:


(lugol preserved, 60/1.4 SPlanApo, Coolpix990)

Best wishes, René.

[Ernst Hippe]

Hallo René,

yes, it is very flat. The picture has been stacked only with 3 photographs, so I am shure now that it is C.radiatus indeed.

[Rene]

Ah, small mistake, I have looked up on my details, the former images (of C radiatus) were made with an immersion objective. So if I say flat, it is really really flat!

Here are some images of what we regard as C (perforatus var.) pavillardii:



And these single shots are made with a 20/0.7 planapo, so comparable in depth of field with a normal 40x lens. This species has a bit of a donut shape with a depressed center. Areolation is slightly denser then in C radiatus. From Cupp: C radiatus:3-4/10um except at the margin (up to 7/10um). C pavillardii: 4.5 center, 3-3.5 midway and 4-5/10um margin.

Good luck, René.