Ceratium cornutum

[Bernd]

A recent mass development of the dinophyte Ceratium cornutum in a local pond provided the material for a series of photographs. Pictures of these dinophytes are difficult to obtain, since they are fast swimmers which also rotate around their longitudinal axis during swimming. If you try to fix them under the coverslip, their armour consisting of several polygonal cellulose plates is easily squashed and their shape thereby destroyed. Since the C. cornutum cells are very thick, you have to rely on stacking images to achieve sufficient depth of focus.
Pictures 1 and 2 show the dorsal (Helicon Focus, stack of 16 images) and ventral view (Helicon Focus, stack of 9 images), respectively. In the dorsal view, the dominant feature in the middle of the cell is the transverse furrow, which is occupied by one of the two flagella of this dinophyte. The other flagellum is pointing backwards. Both flagella are not visible in these images.
C. cornutum is about 125 µm long. The red dots inside the cell are oil droplets, not eyespots.




The plates of the Ceratium armour are all decorated by polygonal areas. To highlight these areas in a photograph, I destroyed the cell contents with diluted sodium hypochlorite solution before taking photos. Picture 3 shows the fine structure of the dinophyte armour (Helicon Focus, stack of 19 images). The insert (100x, Helicon Focus, stack of 5 images) shows one plate of the armour to demonstrate that, according to literature, at the bottom of each polygonal area is pierced by a hole through which an underlying trichocyst can discharge its contents.



Enjoy the pictures

Bernd

[bernhardinho]

Hi Bernd

I sort of forgot to give feedback in the german forum, shame upon me


These shots are absolutely terrific!!

Very well prepared and professionaly photographed !

I bow my head


See you

Bernhard

[BJ]

Bernd,

Some of the very best dinoflagellate photos I have ever seen.

As you say they are very difficult to photograph well. The use of stacking has really paid off.

Congratulations and thank you !

Briano

[discomorphella]

Hi Bernd--

Those are great shots. Dino's are some of my favorite creatures to observe, but I don't get many dinoflagellate blooms around my pond in Oregon. Really nice job on the hypochlorite-cleaned cell too.

--David

[Jbailey]

Bernd:

Those are great shots! Did you stop the subject chemically? I want to try stacking to get better protozoan photos. Refer to my post today "What is it, please?" This organism has too much depth, too.

Thanks

Jim