Last
Tuesday I went to the Waterdienst Lelystad for a microscopy day for the
Nederlandse Sieralgenwerkgroep (the Dutch Desmids Working Group). The working
group visited the estate De Teut in Belgium on Saturday 23rd of June
to take samples.
Sadly I couldn’t participate mainly due to voluntary work that
was planned on the same day and a sprained ankle. I can do a bit of walking,
but I do have problems with grounding when the soil gets uneven. At least I
didn’t want to miss the microscopy day. The expert Ton Joosten handed me some
extra samples to work with afterwards.
I analyzed
one of the samples with a colleague after the microscopy day. One of the most spectacular species is
unmistakably the species of the Micrasterias
genus. In the sample labeled as ‘the ditch’ we found Micrasterias fimbriata.
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| Micrasterias fimbriata Olympus IX81 + DP72 200x immersion-oil EFI-photograph |
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| Micrasterias fimbriata - detail of apical lobe Olympus IX81 + DP72 600x immersion-oil EFI-photograph |
“In the
Netherlands Micrasterias fimbriata is
a rare species, mainly to be encountered in mesotrophic quaking fen regions at
the transition of Pleistocene and Holocene deposits. On a superficial view it
somewhat resembles the more common species Micrasterias
rotata but its habit is more delicate as lobules of the last order are
denticulate instead of emarginated. At the basal and apical semicell angles
those denticulations are even transformed into curved spinules. Cell dimensions
(L x B): 240 μm x 220 μm.” Description
Some of the tiny curved spinules are visible in the more detailed picture below.
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| The spinules are a little bit curved of Micrasterias fimbriata Olympus IX81 + DP72 960x immersion-oil Slide of Z-stack |
