This is not Haematococcus, it is Euglena sanguinea.

This is a stack of 87 images taken with a Zeiss Plan-Neofluar 20x/0,50, Optovar 1,6x, DIC of a living specimen of the diatom Iconella hibernica, previously Campylodiscus hibernicus, collected recently in the river Main close to Frankfurt, Germany.

Greetings, Bernd

Hi Mike,

I do not think that this is a desmid, but a xanthophyte of the genus Pseudostaurastrum.

Bernd

Here are a few pictures showing freshwater centric diatoms from a local pond, either Cyclotella or Stephanodiscus , with very pronounced fibers made of chitin. I showed similar pictures several years ago http://www.photomacrography.net/forum/viewtopic.php?t=12906&sid=6b9f13372fec053448dddc9bdc101d8f...

For me this looks like a half-cell of a Staurastrum desmid, not a diatom.

Bernd

A few days ago I found the desmid algae Arthrodesmus octocornis (= Xanthidium octocorne) in a local pond. http://www.photomacrography.net/forum/userpix/101_Arthrodesmus_01_1.jpg With steep DIC I could see that the cell was embedded in a broad mucilaginous envelope (border outlined by white arrows). ...

The flagellates are attacked by fungal parasites, so-called chytrides.

As Meridion circulare is still very abundant, I took a few images with phase contrast. Not many details, but quite nice overall. http://www.photomacrography.net/forum/userpix/101_Meridion_4_1.jpg http://www.photomacrography.net/forum/userpix/101_Meridion_3_1.jpg http://www.photomacrography.net/forum...

Diatoms of the genus Rhopalodia and Epithemia, both belonging to the family Rhopalodiaceae, are unique in possessing so-called spheroid bodies in addition to plastids and mitochondria in their cytoplasm. The spheroid bodies are proposed to carry out nitrogen fixation for the diatom cell and replicat...

As almost every March I have again revisited my favourite location for the diatom Meridion circulare . The brown, foamy biomass is almost a pure culture of M. circulare if you exclude the ciliates which feast on M. circulare . http://www.photomacrography.net/forum/userpix/101_8_1.jpg Since I like th...

My guess is that the little flagellates actually are zoospores of a parasitic chytrid fungus. The way they move is quite characteristic.

Bernd

Dear Jacek, nice photos! Have you noticed that the specimen on the last image of your post from June, 24th is full of parasites? The many oval objects inside the body of the water flea are most likely Coelosporidium chydoricola , a member of the Haplosporidia. See Green, J. (1974). “Parasites and ep...

Dear Michael, nice series of fotos! However, they do not show reproducing diatoms in a mucilage sheath. Just the opposite. These diatoms have been eaten (ingested) by an amoeba, most likely Leptophrys vorax. These amoebae can ingest an incredible amount of food. Their cytoplasm then is just a small ...

Dear Jacek, your pictures shows Thuricola folliculata. This ciliate is easy to identify, because he lives in a lorica which can be closed with a flap (very clearly visible in the DIC images in the upper third of the lorica, pressing against the ciliate´s body) when the ciliate contracts. It is not t...

The fluorescence image is really beautyful. What exactly does the foto show? An empty theca with the focus on the inside of the ventral plates?

Bernd