While visiting my colleagues in the Netherlands we discussed this peculiar Navicula from the Dutch waters, that I was not able to give a name to. Geurt Verweij – a far more competent diatomist than I ever will be – gave his opinion on the subject: Navicula reinhardtii.
Size= 15 x 34 µm
I had seen this little fellow many times. The structure in the middle of the scale is quite special, with long an short striae. Geurt pointed out, that the end of the raphe is curved. Yes, I could see that. And, what’s even more specific is that the other end is curved to the opposite direction. Seems to be exceptional for Navicula s. str., according to Lange-Bertalot (2001). With some difficulty I could see even this. I mean the raphe curving the other way, not the exceptionality in it.
So, there is a new diatom-buddy for me. Navicula reinhardtii (A. Grunow) A. Grunow in P.T. Cleve et J.D. Möller 1877. According to the Dutch TWN-list there are no synonyms, but in both the books, Süsswasserflora 2/1 (1997) and Diatoms of Europe (2001) Stauroneis reinhardtii is mentioned as a synonym. Hmm…
Here is some more information about this species: Common Freshwater Diatoms of Britain and Ireland A multiaccess key. Seems to be very sensitive to pollution, according to the France IPS, and alkalibiontic. No wonder I’ve not seen it in Finland. 😉
Literature:
Krammer, K. & H. Lange-Bertalot, 1997. Bacillariophyceae. 1.Teil: Naviculaceae. Julk.: Ettl, H.,
Gerloff, J., Heynig, H. & Mollenhauer D. (toim.). Süsswasserflora von Mitteleuropa,
Band 2. Stuttgart, Gustav Fischer Verlag, Jena. 876 s.
Lange-Bertalot, H. 2001. Diatoms of Europe, Volume 2: Navicula Sensu Stricto, 10 Genera Separated from Navicula Sensu Lato, Frustulia. A.R.G Gantner Verlag K.G., Ruggel. 526 s.