More Actinocyclus Photos


Richard Carter
 

I've added a few more images of Actinocyclus species, to further illustrate some characteristics of the genus.  To the image of A. roperi that I put up to illustrate large rimoportulae I have added another image at a different focus level.  As you can see in this new image, this species is weakly fasciate at best.  We are looking at the interior of a single valve.  A. cholnokyi (synonym: Coscinodiscus divisus) has no apparent pseudonodulus under the light microscope.  It has a clear central annulus, and is strongly center-fasciate.  A. ellipticus is another weakly fasciate (at best) species, but has an annulus and an especially wide submarginal band of smaller areolae.  A. octonarius is especially interesting: it is center-fasciate, with a clear annulus and a large pseudonodulus.  Big specimens are usually very brightly colored -- I'll try to add a photo of one of these larger specimens later.  The photo of A. pyrotechnicus was made from a fantastic type slide mounted by Raymond.  This is one of the larger species, with a big annulus and rather small pseudonodulus.  The color at the scope is usually brown.

I hope you find these images to be of interest!

Dick Carter


Rob Kimmich <kimmich46@...>
 

I put up a public folder, Actinocyclus, and included two from Hawaii that I labelled based on images from West Pacific Diatom Project. These don't seem to have much of a central annulus but show the pseudonodulus pretty well, I think. Dick, maybe you would like to duplicate your Actinocyclus in there for species comparisons. You can see I'm experimenting again with ways to present our images.
 
I'm trying to understand "fasciate" as it relates to diatoms. My higher plant books suggest a fascicle is a bundle of stems grown together. Does it refer to the gathering of the striae in the center?
 
Rob K
 

----- Original Message -----
Sent: Monday, April 04, 2011 10:02 PM
Subject: [diatom_forum] More Actinocyclus Photos

 

I've added a few more images of Actinocyclus species, to further illustrate some characteristics of the genus.  To the image of A. roperi that I put up to illustrate large rimoportulae I have added another image at a different focus level.  As you can see in this new image, this species is weakly fasciate at best.  We are looking at the interior of a single valve.  A. cholnokyi (synonym: Coscinodiscus divisus) has no apparent pseudonodulus under the light microscope.  It has a clear central annulus, and is strongly center-fasciate.  A. ellipticus is another weakly fasciate (at best) species, but has an annulus and an especially wide submarginal band of smaller areolae.  A. octonarius is especially interesting: it is center-fasciate, with a clear annulus and a large pseudonodulus.  Big specimens are usually very brightly colored -- I'll try to add a photo of one of these larger specimens later.  The photo of A. pyrotechnicus was made from a fantastic type slide mounted by Raymond.  This is one of the larger species, with a big annulus and rather small pseudonodulus.  The color at the scope is usually brown.

I hope you find these images to be of interest!

Dick Carter


Raymond <ortholux@...>
 

Nice collection of photos! Thanks for sharing.

It was about time for me to create a photo album of my own, and as a first photo I added another shot of the same A. pyrotechnicus specimen that you photographed. It illustrates the brown colour mentioned.

I wonder why it was named 'pyrotechnicus'. Could it be because the areolae pattern sort of looks like the burst of a fireworks rocket?

Cheers,
Raymond




Op 5-4-2011 7:02, Dick Carter schreef:

I've added a few more images of /Actinocyclus/ species, to further
illustrate some characteristics of the genus. To the image of /A. roperi
/that I put up to illustrate large rimoportulae I have added another
image at a different focus level. As you can see in this new image, this
species is weakly fasciate at best. We are looking at the interior of a
single valve. /A. cholnokyi/ (synonym: /Coscinodiscus divisus/) has no
apparent pseudonodulus under the light microscope. It has a clear
central annulus, and is strongly center-fasciate. /A. ellipticus/ is
another weakly fasciate (at best) species, but has an annulus and an
especially wide submarginal band of smaller areolae. /A. octonarius/ is
especially interesting: it is center-fasciate, with a clear annulus and
a large pseudonodulus. Big specimens are usually very brightly colored
-- I'll try to add a photo of one of these larger specimens later. The
photo of /A. pyrotechnicus/ was made from a fantastic type slide mounted
by Raymond. This is one of the larger species, with a big annulus and
rather small pseudonodulus. The color at the scope is usually brown.

I hope you find these images to be of interest!

Dick Carter


Richard Carter
 

Raymond,

Wow, nice photo!  Mine doesn't capture the fine size of the areolae at all, but yours really does the trick!  I didn't try to keep the color, as I was using a filter to try to improve the resolution -- a waste of time when I miss the focus that badly...............

I think you are right about the origin of the name.  To me, the bright diffraction colors of an A. octonarius, coupled with the same type of "pyrotechnic" striae, looks even more like fireworks.

I hope we will get to see a lot more of your images!

Dick


--- On Tue, 4/5/11, Raymond wrote:

From: Raymond
Subject: Re: [diatom_forum] More Actinocyclus Photos
To: diatom_forum@...
Date: Tuesday, April 5, 2011, 2:30 PM

Nice collection of photos! Thanks for sharing.

It was about time for me to create a photo album of my own, and as a
first photo I added another shot of the same A. pyrotechnicus specimen
that you photographed. It illustrates the brown colour mentioned.

I wonder why it was named 'pyrotechnicus'. Could it be because the
areolae pattern sort of looks like the burst of a fireworks rocket?

Cheers,
Raymond




Op 5-4-2011 7:02, Dick Carter schreef:
> I've added a few more images of /Actinocyclus/ species, to further
> illustrate some characteristics of the genus. To the image of /A. roperi
> /that I put up to illustrate large rimoportulae I have added another
> image at a different focus level. As you can see in this new image, this
> species is weakly fasciate at best. We are looking at the interior of a
> single valve. /A. cholnokyi/ (synonym: /Coscinodiscus divisus/) has no
> apparent pseudonodulus under the light microscope. It has a clear
> central annulus, and is strongly center-fasciate. /A. ellipticus/ is
> another weakly fasciate (at best) species, but has an annulus and an
> especially wide submarginal band of smaller areolae. /A. octonarius/ is
> especially interesting: it is center-fasciate, with a clear annulus and
> a large pseudonodulus. Big specimens are usually very brightly colored
> -- I'll try to add a photo of one of these larger specimens later. The
> photo of /A. pyrotechnicus/ was made from a fantastic type slide mounted
> by Raymond. This is one of the larger species, with a big annulus and
> rather small pseudonodulus. The color at the scope is usually brown.
>
> I hope you find these images to be of interest!
>
> Dick Carter
>
>


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Rob <kimmich46@...>
 

Nice, Raymond. The areolae start to show up. Yes, I would say fireworks.

Rob

--- In diatom_forum@..., Raymond <ortholux@...> wrote:

Nice collection of photos! Thanks for sharing.

It was about time for me to create a photo album of my own, and as a
first photo I added another shot of the same A. pyrotechnicus specimen
that you photographed. It illustrates the brown colour mentioned.

I wonder why it was named 'pyrotechnicus'. Could it be because the
areolae pattern sort of looks like the burst of a fireworks rocket?

Cheers,
Raymond




Op 5-4-2011 7:02, Dick Carter schreef:
I've added a few more images of /Actinocyclus/ species, to further
illustrate some characteristics of the genus. To the image of /A. roperi
/that I put up to illustrate large rimoportulae I have added another
image at a different focus level. As you can see in this new image, this
species is weakly fasciate at best. We are looking at the interior of a
single valve. /A. cholnokyi/ (synonym: /Coscinodiscus divisus/) has no
apparent pseudonodulus under the light microscope. It has a clear
central annulus, and is strongly center-fasciate. /A. ellipticus/ is
another weakly fasciate (at best) species, but has an annulus and an
especially wide submarginal band of smaller areolae. /A. octonarius/ is
especially interesting: it is center-fasciate, with a clear annulus and
a large pseudonodulus. Big specimens are usually very brightly colored
-- I'll try to add a photo of one of these larger specimens later. The
photo of /A. pyrotechnicus/ was made from a fantastic type slide mounted
by Raymond. This is one of the larger species, with a big annulus and
rather small pseudonodulus. The color at the scope is usually brown.

I hope you find these images to be of interest!

Dick Carter