a marine alga: Halosphaera sp.

Franz Neidl · Post by **Franz Neidl** » Sat Oct 29, 2011 1:15 pm

This is a stage of the alga Halosphaera sp. - a very complicated organism. To be honest: I have the feeling that I will never understand its life cycle. It has also a period with flagellates, sometimes it changes the colour in yellow ecc...
2 pictures

Franz

Charles Krebs · Post by **Charles Krebs** » Mon Oct 31, 2011 11:59 am

Franz,

These shots really capture the spherical shape of this green alga.

To be honest: I have the feeling that I will never understand its life cycle.

As with the Hydrurus shots Grant recently posted, some of these alga have surprising different forms at various stages.

Franz Neidl · Post by **Franz Neidl** » Mon Oct 31, 2011 2:24 pm

Thank you Charles. You are right.
This alga is really difficult. Therefore I publish here again two pictures from last year from other stages of the same genus Halosphaera. One can see the differences!

Franz

René · Post by **René** » Tue Nov 01, 2011 8:52 am

These are beautiful images, Franz. The first of the last two images I think shows a double wall with pores. That would make it Pachysphaera, which is more related to Pterosperma than to Halosphaera.

Best wishes, René

Franz Neidl · Post by **Franz Neidl** » Tue Nov 01, 2011 10:25 am

Hello Renè,

I am very happy about your help. Pachysphaera (syn. Tasmanites) seems to me very probable because it is a member of the same family like Halosphaera - the Prasinophyceae.

Thank you !
Franz

René · Post by **René** » Tue Nov 01, 2011 10:43 am

oh yes, definitely closely related. And you've got quite a good collection of images from this family together of thingies we rarely come across (Northsea).

BTW, the old class Prasinophyceae will probably fall apart soon, it's polyphyletic. These organisms will however be retained together within the Halosphaeraceae.

Best wishes, René