Microgromia 1

Most likely ID: n.a.


Synonym: n.a


Sampling location: Simmelried


Phylogenetic tree: n.a.



  • shell retort-shaped, outline circular or pyriform
  • length of shell 14 – 20 µm
  • shell hyaline, colored orange-brown, without iron precipitation on older specimens
  • long neck, obliquely oriented to shell outline, annulated, distal end with thickened rim
  • nucleus central
  • contractile vacuole near neck

No drawings from previous authors available.

Microgromia 1 I have found exclusively in the Simmelried and this only until 2007. After that I have found no more specimens. This species is clearly different from the Microgromia species described by de Saedeleer. The shell of this species is always orange-brown colored, but without obvious iron deposits as in Microgromia haeckeliana. The neck is clearly angled. Its length is about a quarter of the shell length. It is also distinctly annulated, giving it a wavy appearance in optical section. The cell is often placed at the dorsal end of the shell and a long cytoplasm peduncle leads to the neck. I could not definitively detect a septum, as I only had a dry condenser in 2007, which prevented me from achieving the necessary resolution for detection. However, the described characteristics suggest this species to be a representative of the genus Microgromia.


Fig. 1: Microgromia 1. L = 14–20 µm. Six different specimens. All of them are colored orange-brown. Note the annulated neck (AN) of this species. Nu = nucleus. Obj. 100 X.


Fig. 2: Microgromia 1. L = 17 µm. This specimen tries to ingest a small alga caught with a thin granuloreticulopodium. Obj. 100 X.


Fig. 3: Microgromia 1. L = 14 µm. A specimen attached to an alga filament. Note the almost vertically angled neck of the sessile specimen. Obj. 100 X.