Diatom: Pinnularia in Valve & Girdle View

[KurtM]

I'm posting this for several reasons; first, forum contributor wporter asked for results using the dishes he generously did a group buy on, and these images were made using one (see: viewtopic.php?f=16&t=6332 ). Secondly, it's a bit of an amusing story: I was imaging an intact, but quite empty, Pinnularia frustule as seen in valve view, in a live sample, when an obliging ostracod came along and knocked it over on its side, which left it in an excellent girdle view pose - thanks, seed shrimp (always thought that a curious thing to call them)! Thirdly, because it's a rare opportunity to get a clear shot at valve and girdle view of a perfectly intact frustule that's clear of distracting contents within.

Both images are stacks, shot through the 40x, DIC, Diaphot TMD inverted.

[Hobbyst46]

Indeed a very beautiful demonstration of the valve vs. girdle view.

[rnabholz]

Lucky chance, well taken advantage of by our newest UDM.....Upside Down Microscopist.

Really good images for a diatom "on the hoof" that is to say, not mounted.

Hard to beat Pinnularia for great detail in that cool structure.

Nicely done Kurt.

[75RR]

You have done credit to that 'fortunate event' Great to see both views of exact same diatom.

Speaking of which ... how feasible/practical is it to do a temporary 'wet' strew in distilled water using your Australian microscope?
Might it even be possible to put the seed shrimp out of a job with a glass needle?

[KurtM]

Australian microscope

^^^

As a matter of fact, Mr. Charles Suslavage would call your proposal an entirely feasible one, see:
http://www.microscopy-uk.org.uk/mag/ind ... atoms.html

However, the real trick here was finding a fully intact frustule with nothing inside to obscure surface features. Now that I think about it, I suppose it's not only doable to achieve empty but intact diatom shells (starve them out?), but probably ought to be tried as an experiment - coupled with mastery of 'upending' them. Maybe a project for this winter.

One thing I can't help but notice and wonder at: raphae tend to fade to near-invisible, are extremely difficult to see or capture on images, except on cleaned and separated valves. A good example of how important separating frustules into component parts is in the cleaning process, see how much more detail is visible in the following image from 2016: