Help with identification please

[MikeBradley]

I found numerous specimens of this specimen in a garden pond sample recently but I'm having trouble identifying it. I can't find anything like it, this small, in my usual guides. I wonder whether someone on the forum may be able to help?
The groups were mostly like this one, about 600 microns diameter with the filaments 7-9 microns across. There were fragments around as well. The image here was a stack of 20 images at 10X 0.30na. Thanks
Michael

Unknown10x.jpg (163.09 KiB) Viewed 2908 times

[dtsh]

My wild guess, cyanobacteria; don't know I'd put much stock in my guess though.

[DrPhoxinus]

Cladophora?

[charlie g]

Hi, Michael, looking at your image as a clock-face...at 12-o-clock, 2-o-clock, 5-o-clock...and most clearly at 9-o-clock...your image shows terminal branches which end with clear-non pigmented long tapering hair cells.

I suggest this is a freshwater algae in the genus: Stigeoclonium.

"How to Know the Fresh-Water Algae", G.W.Prescott, 1954/1964, pg 122 , my quickie source.

Expanding upon this, and Dr.Prescott's remarks on variable morphology of this genus ( Stigeoclonium)...I dusted off my " a biology of the algae" ( publisher choice to use lower case letters on this great text),philip sze ( again, publisher

prints in lower case...hmmm, I like this style...I have other texts which use lower case letters in the title/ cover of the text), 1986.

Dr. Sze, georgetown university ( again, text prints in lower case) mentions on pg 60: 'Stigeoclonium shows considerable morphologic variation depending upon environmental conditions. When nutrient levels are low in surrounding waters, the erect-system of filaments is more branched...and branches often terminate in long tapering hairs composed of cells with no pigment'.

This algae has a a 'basal-prostrate filament morphology' different from it's 'erect system of filaments'...Michael...please with a lower mag objective in a deep droplet of sample water...try to observe the under-side of this image you kindly posted...the algal filaments should look different...more rounded cells in the 'basal branches'....this variety of form in algae, in this algae is termed: "heterotrichy" ( use this term in a game of Scrable!?).



Please tell me...in B.C. you collected from a pond 2/22?!! Did you collect from under ice as I often do? all the best, charlie g., finger lakes/US

[DrPhoxinus]

You are a better taxonomist than I Gunga Din

[charlie g]

Hi, doc phlox...what's with : 'Gunga Din'...I saw the movie on black and white tellie as a child/ aLL THE BEST, CHARLIE G

[DrPhoxinus]

Just Homage to an paragon

[charlie g]

I guess the perception of negative baggage in most remarks are in the eyes of the chap addressed, my bad. respectfully, charlie g

[DrPhoxinus]

I meant no insult.
Only your expertise in solving the problem impressed me.

Sorry

[MikeBradley]

DrPhoxinus, Charlie, thank you both for the suggestions. The sample does seem to match the descriptions of Cladophera (branching, not tufted, net like chloroplasts). However it also has the tapered filament tips, sometimes acutely so and transparent, of Stigeoclonium. Unfortunately the sample has been disposed of now, so a more detailed examination isn’t possible, but I will try to collect some more and investigate further. Thanks very much to you both for your help.
Michael