An interesting group of testate amoebae is the genus Difflugia. There have been described hundreds of species, but the question is: how many of them are true species? Most descriptions are inaccurate of just based on one single test. Probably this group consists of several genera. Only DNA sequencing can help here. One of my projects is to make a visual map of all known species. It’s one of the most difficult taxa to identify.
A. rotundistoma, from Korganova, 1987 Genus Apolimia Korganova, 1987 Diagnosis: Shell ovoid, quite large, opaque, round in cross section, densely covered with round or oval
E. bidens, 315 and 270 µm, Naardermeer, the Netherlands Genus Erugomicula Nasser, Gregory, Singer, Patterson and Roe, 2021 Typespecies: Erugomicula bidens (Penard, 1902) Diagnosis: laterally-compressed,
Two shells from the same sample, 310 µm (Naardermeer, Netherlands) Erugomicula bidens (Penard, 1902) Basionym: Difflugia bidens Penard, 1902 Diagnosis: Test ovoid, compressed in cross-section,
Infraorder Cylindrothecina González-Miguéns et al., 2022 Diagnosis: can be diagnosed by its specific sequences of the mitochondrial and nuclear DNA markers (COI, NADH and
Specimen with an optical cross-section of the peduncle (left) Organic-walled species Diagnosis: Multinucleated organic-walled monothalamous foraminifera. Test spherical to oval shaped, with a hyaline, flexible,
V. tyrolensis, two specimens Velamentofex tyrolensis Völcker and Clauß, 2020 April 2022, I found two specimens in a sample from the pond in Crailoo, Netherlands. I could
Raphidiophrys n. sp. Raphidiophrys n. sp. Diagnosis: Plate-scales canoe-shaped, elongated, with tapering, rounded poles, slightly curved upwardly. Light microscopically, these plate-scales show a clear rim;
Lacogromia sp., Naardermeer, the Netherlands, 2022 (n=nucleus) Lacogromia sp. Six living specimens were found in an old sediment sample from a freshwater ditch in nature
S. rhombophora , after Bonnet, 1966 Sphenoderia rhombophora Bonnet, 1966 Diagnosis: Test hyaline, ellipsoidal, very slightly compressed. Fundus relatively narrow. Pseudostome largely truncated. Neck very
S. ovoidea , after Jung, 1942 Sphenoderia ovoidea Jung, 1942 Diagnosis: Shell with four layers of plate-scales. Distinguished from S. fissirostris by the ovoid tapering