Microgromia 1
Most likely ID: n.a.
Synonym: n.a
Sampling location: Simmelried
Phylogenetic tree: n.a.
Diagnosis:
- 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 clear iron deposits as in Microgromia haeckeliana. The neck is clearly angled. It has a length, which is about a quarter of the shell length. It is also distinctly ringed, 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 speak for 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 try to ingest a small alga catched with a thin filopodium. 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.