
Difflugia rubescens, feeding on an algae
Difflugia rubescens Penard, 1891
= Pseudonebela rubescens new comb.?
Diagnosis: Shell pyriform, yellow or light brown in color; membrane chitinous, encrusted with foreign particles and diatoms. Aperture circular, bordered by a incurved crenulate margin; protoplasm usually containing numerous granules of brick-red color; cyst equally red or brownish-red in color.
Dimensions: In the literature: Shell length 65-105 µm; width 38-54; diameter of aperture 14-20 µm.
Ecology: Freshwater. Aquatic vegetation and among Sphagnum or moss.
Remarks: Difflugia rubescens makes holes in filamentous algae and engulfs their content.
This is probably a Pseudonebela species. See Siemensma and Opitz, 2014.


Difflugia rubescens, pseudostome, Austria (l) and Netherlands (r)


Difflugia rubescens, pseudostome, Cardet, France, 2019


Pseudostome, Dutch specimen (l), other test from Cardet, France 2019 (r)

Difflugia rubescens, 83 µm, the Netherlands

Difflugia rubescens, stacked image – Tirol, Austria

Difflugia rubescens, feeding on a Closterium – The Netherlands

Difflugia rubescens – The Netherlands

Difflugia rubescens, but probably Pseudodifflugia africana, feeding on a Closterium – Drawing A. A. De Groot, collection Ferry Siemensma

Diffliugia rubescens – 70m long, with cyst; Austria, Tirol

Difflugia rubescens with double pseudostome

Difflugia rubescens, 75 µm; Tirol, Austria

Difflugia rubescens, total length 154 µm – Tirol, Austria


Difflugia rubescens, Haaksbergen, Netherlands 2018