Fossula arctica

There were so many exciting things happening during the first two weeks of the semester, the diatoms went forgotten and unappreciated.So the diatom of this week is Fossula arctica G.R.Hasle, E.E.Syvertsen & C.H.von Quillfeldt 1996, just to remind us of Arctic cold waves that are coming.

It is one of the most abundant diatom species in the Arctic, but it was described only 20 years ago! Untill them it was clumped together with Fragilariopsis (Nitzschi-like diatoms with canal raphe) AND Fragilaria (araphids)! Just some other semi-transparent pennate...

But this particular pennate is set apart from all others by one rimoportula per valve and peculiar structure of its mantle. Though it's hard to tell under LM.

The most useful paper: Hasle, G.R., E.E. Syvertsen & C.H. von Quillfeldt (1996) Fossula arctica gen. nov. spec. nov., a new marine Arctic araphid diatom, Diatom Research 11 (2): 261-272,

DOI: 10.1080/0269249X.1996.9705383