Pediastrum alga - 2nd species

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NikonUser
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Location: southern New Brunswick, Canada

Pediastrum alga - 2nd species

Post by NikonUser »

Another Pediastrum from a local pond.
Looks incomplete but obviously has far more individual cells than my previous Pediastrum
HERE

Oly 40x SPlan Apo, NFK 2.5x eyepiece, 6 frames @ 0.001 mm, ZS PMax
Image
NUM10032
NU.
student of entomology
Quote – Holmes on ‘Entomology’
” I suppose you are an entomologist ? “
” Not quite so ambitious as that, sir. I should like to put my eyes on the individual entitled to that name.
No man can be truly called an entomologist,
sir; the subject is too vast for any single human intelligence to grasp.”
Oliver Wendell Holmes, Sr
The Poet at the Breakfast Table.

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ABEL
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Post by ABEL »

Hello

It is enormous ¡¡¡ :shock: :shock:

Very good photo also. A lot of for time I not veia such a big pediastrum.

Mitch640
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Joined: Sun Aug 15, 2010 1:43 pm

Post by Mitch640 »

Wow, that's the biggest one you've posted since I got here. Can they theoretically just keep getting bigger and bigger, or is this a fluke? I'm waiting for the day I find one of these. :)

NikonUser
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Location: southern New Brunswick, Canada

Post by NikonUser »

Thanks Abel and Mitch.

The specimen was actually longer than shown but that was all I could get into the frame.
The actual length was 0.192 mm but I believe there were still some cells missing.

I believe each species has a fixed maximum number of cells; but this is only the 2nd specimen of Pediastrum I have seen.

Did you notice how those outside cells join together? A cog pattern as seen on the lower right edge.
NU.
student of entomology
Quote – Holmes on ‘Entomology’
” I suppose you are an entomologist ? “
” Not quite so ambitious as that, sir. I should like to put my eyes on the individual entitled to that name.
No man can be truly called an entomologist,
sir; the subject is too vast for any single human intelligence to grasp.”
Oliver Wendell Holmes, Sr
The Poet at the Breakfast Table.

Nikon camera, lenses and objectives
Olympus microscope and objectives

Mitch640
Posts: 2137
Joined: Sun Aug 15, 2010 1:43 pm

Post by Mitch640 »

I see the cog, or it's probaby a toothed plate. One of the strongest ways to connect to parts to each other. Caterpillar uses the same connection to bolt two track ends together. I have never seen one of those break.

Also, look straight across. There is a cell, with nothing in it.

rekuwi
Posts: 83
Joined: Mon Jan 12, 2009 9:22 am
Location: Wiesbaden, Deutschland

Post by rekuwi »

Hallo NU,

Pediastrum angulosum can have 8 - 128 cells, colonys untill 400 µm.

best regards
Regi

NikonUser
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Joined: Thu Sep 04, 2008 2:03 am
Location: southern New Brunswick, Canada

Post by NikonUser »

Hi Regi
I was trying to emphasize the maximum number of cells.
Presumably each colony starts with one cell, it divides (mitosis) to give 2 and then by exponential growth (correct term?) 2 becomes 4, 4-8, 8-16. 16-32, 32-64, 64-128.
No more cell division after 128 cells?
NU.
student of entomology
Quote – Holmes on ‘Entomology’
” I suppose you are an entomologist ? “
” Not quite so ambitious as that, sir. I should like to put my eyes on the individual entitled to that name.
No man can be truly called an entomologist,
sir; the subject is too vast for any single human intelligence to grasp.”
Oliver Wendell Holmes, Sr
The Poet at the Breakfast Table.

Nikon camera, lenses and objectives
Olympus microscope and objectives

rjlittlefield
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Post by rjlittlefield »

NikonUser wrote:exponential growth (correct term?)
Exactly correct.

In math and science, the word "exponential" describes a growth or decay function whose value multiplies by some constant factor in some fixed amount of time. Equivalently, the amount you add or subtract is proportional to how much you currently have.

In casual speech, "grew exponentially" is often used to mean something like "grew quickly to be a lot larger", regardless of whether the growth pattern was even close to exponential in the math/science sense.

--Rik

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