Aquatic fungi parasitic on desmids – Ancylistes?

[Bernd]

Dear all:

In the german microscopy forum there recently was a thread on fungal parasites of algae (http://www.mikroskopie-forum.de/index.php?topic=4389.0), and for me it was not a surprise that none of the parasites shown there could be named. Therefore, I would like to show here pictures taken with brightfield illumination of a desmid algae of the genus Closterium killed by a parasitic fungus. The first image shows the whole Closterium cell, about 525 µm in length and full of parasites. The other two pictures are close-ups of the parasites, the circular structures having a diameter of about 17 µm.







I did some literature reserch and found out the the parasite might be the fungus Ancylistes closterii and the circular structures actually may be oogonia. Are there any experts who can either confirm my determination or, if it is incorrect, know the genus of the fungus shown here?

Bernd

[Ferry]

Hi Bernd,

Very nice pictures and interesting information. You may be right. Today I came across similar fungi, also in Closteriums. I will have a look again. Thanks!
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[Franz Neidl]

About this topic exists a useful article in Internet:
http://www.desmids.nl/info/fungal_parasites/fungal_parasites.html
Interesting is the chapter "Fungi living on and in algae", in:Hilda Canter-Lund, John WG Lund: Freshwater Algae, their microscopic world explored, Bristol 1995, p.279-324.

Franz

[Gyrosigma]

Hello Bernd,

I am not a specialist, but I found in an old French book "Microscopie pratique (G.Deflandre)" reference to Closterium parasites and yours seems to be Ancylistes Closterii.
So, according to my small documentation, I confirm your determination

best regards from France

Dominique

[Ferry]

Ha Dominique,

That's a funny coincidence. I also used that old French book of Deflandre this weekend. It's still very usefull for UMO's (Unidentified Microscopic Objects)

Ferry
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