mystery object

[René]

Time for a little quiz, anyone? UV-fluorescence, crop is 50x50um.

Best wishes, Rene.

[Jan Kros]

Helle René

Is this a Dynoflagellate?

Greetings
Jan

[René]

Indeed, Jan. The fluorescence is due to the optical brightener calcofluor white, which stains the cellulose parts of the dinoflagellate.

Now, this was a difficult one, I admit. With the corresponding brightfield images one should be able to get to genus:





Best wishes, Rene.

[René]

Still no bells ringing?? I pushed it over with my needle, now it should make more sense:




It's the dinoflagellate Dinophysis rotundata from the North Sea, the diatom left to it is Rhizosolenia (=Guinardia) delicatula. Not one of the dinoflagellates that needs fluorescent staining for identification, but I have never had the luck before that it stood exactly on it's 'head' and the fluorescent staining made some details (especially pores) visible.

This is a heterotrophic sp while most other Dinophysis sp are autotrophic. It is a parasite by sucking the contents out of its (living) prey with a straw. Yuk!

Next time better luck guessing,
Rene