Microworld

world of amoeboid organisms

Menu
Quadrulella longicollis, 147 um long, stacked

Quadrulella longicollis Taranek, 1882

Diagnosis: Much larger than Q. symmetrica and with straight sides, usually without pronounced lips.

Dimensions: c. 150 µm.

Ecology: mosses, fresh water.

Remarks: The specimens below were collected from the Heelsumse Beek, a clear stream near the city of Arnhem. These shells were the only Arcellinida which were found in a thin layer of sediment in this oligotrophic stream, fed by pure groundwater. The shell length ranges from 69-147 µm. The two smaller ones are Q. symmetrica, the largest three are Q. longicollis. Kosakyan et al (2012) found genetic distances, up to 11%, between Q. symmetrica and Q. longicollis.

These records from one location suggest rather a species complex than distinct intraspecific diversity.
Recent posts

Metaheleopera

M. ovalistoma – after Bartos, 1963 Metaheleopera  Bartos, 1963 Diagnosis: Shell clearly narrowing towards the pseudostome, which can be seen even more clearly on the narrower sides

Read More »

Matsakision radixicola

M. radixicola – after Chardez, 1974 Matsakision radixicola  Chardez, 1974 Diagnosis: Shell ovoid, slightly compressed, transparent; pseudostome oval, truncated perpendicularly, with a slight neck. Shell

Read More »

Matsakision cassagnaui

M. cassagnaui – after Bonnet, 1967 Matsakision cassagnaui  Bonnet, 1967 Diagnosis: Shell hyaline, elongated ovoid, very little compressed, truncated perpendicularly or very slightly obliquely in

Read More »

Matsakision

Matsakision – after Bonnet, 1967 Matsakision   Bonnet, 1967 Diagnosis: Shell hyaline, elongated ovoid, very little compressed, truncated perpendicularly or very slightly obliquely in the region

Read More »

Arcella marginata

Arcella marginata, after Deflandre, 1929 Arcella marginata Daday, 1905 Diagnosis: Shell roughly hemispherical, rather overhanging, with a flattened, smooth edge. In dorsal view showing a

Read More »

Arcella lobostoma

Arcella lobostoma, after Deflandre, 1929 Arcella lobostoma Deflandre, 1929 Diagnosis: Shell hemispherical. In ventral view, irregular circular outline, often a little elliptical; pseudostome irregularly lobed:

Read More »