the marine diatom Detonula pumila (?) ed.: Lauderia annulata

Franz Neidl · Post by **Franz Neidl** » Fri Jan 20, 2012 10:02 am

I would be glad to know if this is the marin diatom Detonula pumila.
The whole chain was 240 µm long.
two pictures:
Obj. 40x, DIC
Obj. 20 Ph, crop
marine plankton

Franz

René · Post by **René** » Fri Jan 20, 2012 10:25 am

No, that's Lauderia annulata. It is sometimes hard to see the difference as the connecting process between two cells of Detonula is not always good visible. But there are two other signs in your images: the mucus from the marginal processes spreading out, away from the cells, and the nucleus, which in Lauderia always is symmetrically spread to both sides (typically with a nucleolus at both cell ends). In Detonula it is concentrated in one end of the cell.

Best wishes, René