Rhopalodian Diatom Images

[KurtM]

Rod got me all interested in studying Rhopalodians again. I'm glad of it, as it's a genus I have a tendency to avoid for two reasons: first, because it's so common, and familiarity breeds contempt - something to ever be on guard against. Secondly, it's quite a thick, bulky, confusing form that defies efforts to make sense of its morphology.

Diatoms are the very devil to make stacked images of too, owing to the transparency of the (microscopic) glass seashells. I made more images than I care to admit to in order to arrive at the two Rhopalodia stacks I offer here. This is to speak highly of Rod's imaging and post processing skills, incidentally. One other note: none of the images were cropped. I guess I have a peculiar talent for selecting individuals that just fit into the frame. Light levels were only slightly tweaked, saturation left alone, and sharpening judiciously applied to the single frame shots only.

All images are through the 100x/1.25 lens. The first is DIC, the second DIC and 1st order red compensator. The last two are just for fun, single frames, the first DIC and the last DIC with 1st order red compensator. Nobody can resist a good Nitschoid, and it says in the Constitution of the United States that all Gomphonema articulatum must be presented whenever possible.

[rnabholz]

I would be very pleased to call any one of these mine. All are beautifully done.

Your DIC really digs out the details. The texture visible on the "piano key" like structures that line the full length of the frustule are very hard to resolve. Definitely showing here.

I was not aware of the federal peril I was putting myself in by passing on the occasional Gomphonema. I don't want no trouble.

[zzffnn]

Nice images, thank you for sharing, Kurt.
Happy new year to you and all members!

[75RR]

You have managed to tease out some fine detail. Nice!

[billben74]

Beautiful images.
I can concur on the stacking issues with diatoms. They are their own distorting lens.
They can present problems stitching as well, for the same sort of reasons- > keeping the images similar between multiple stacks is tricky. (I'm struggling with such an issue...)

As you mention the Rhopalodians may be common but as your images show, they are not commonly beautiful.

[KurtM]

Thanks for the kind comments, all!

Fan, are you back home now?

Billben74, I had you and your recent Kemp diatom images - which were quite nicely done, by the way - in mind when I made those stacking comments.

Here's one more stack. The ID for this one eludes me, all I can say is it's definitely a freshwater form, obtained in the same sample as all the others shown above, which was taken from Canyon Lake, in central Texas, back in July 2014.

[billben74]

Another beauty.

[exmarine]

Kurt,
I must commend you on an absolute fantastic set of prints of diatoms and the last one which appears to be stacked I think could be Orthoseira dendrophila or a species of Melosira. I can not be sure of either species.
The whole set of photos are a credit to your commitment to producing good clean diatoms for others and yourself to study. Well done Kurt your a fine example for others to follow.

Great set of photos.

I think I have the correct I. D. for the last diatom its Aulacoseira sp.