Spiral algae help please!

[ziggythecat]

Hi, can anyone help with identification of this algae please?

Its from a city lake which has quite a good mix of other plankton in it - colonial greens, volvox, couple of blue-green species etc.. But this is v abundant.
Sample was taken this week so water temp was about 15-18C.

The spirals are fixed, its pretty rigid. The cells are about 5um wide.

Its really niggling me that I can't id it. I've a bit of video of it too. Any help would be v much appreciated.

Thanks

[Bruce Taylor]

Spirulina.

[ziggythecat]

Thanks. That's what I first thought of - it's what I'd name it if it didn't have a name

But its just too big - 5um or even a bit more whereas spirulina is more 1-2um wide.

I want to call it a Tribonema but can't find one that 'fits'

[Bruce Taylor]

Ah, and on closer look, it appears to have chloroplasts, so it's a eukaryotic green alga, not a cyanobacterium.

So...carry on. (Algae are not in my wheelhouse...I should know better than to comment on 'em. )

[ziggythecat]

thanks for commenting, it all helps.

I was really only looking at the cyanos, but this looked like it should be a definite 'tah dah thats what it is' and now its bugging me!

cheers