Difflugia diafana

 

Drawings after Vucetich (1987); the photographed tests were found in the Netherlands (2017) in a population of Difflugia longum.

 

 

Difflugia diafana  Vucetich, 1987

= Difflugia longum Chardez, 1987?

 

Diagnosis: Test elongated, yellowish gray, with flanks almost parallel. In lateral view compressed, accentuating more this character towards the posterior region, which ends in two long, somewhat diverging spines or horns. Anterior region with has a short but well-defined neck; pseudostome oval. Test covered by small and thin exogenous particles and by some detritus of organic origin. Overall the coating is poor, since the exogenous particles are not very abundant, usually they are not juxtaposed and leave the organic matrix partly uncovered, making the test delicate and very transparent.

 

Dimensions: Length 210-235 µm; width 108-114 µm; spines 50-60 µm long; neck 17-22 µm; aperture 48-52 µm; my measurements 240 and 298 µm (n=21).

 

Ecology: Northern Argentina (1987), the Netherlands (2015-2017).

 

Remarks: I think that D. diafana is identical with D. longum. I have found similar two-horned tests within a population of D. longum (see below). Unfortunately, Vucetich didn't give any additional information.

 

Difflugia acutissima longum

 

D. longum: all shells are from the same sample (Naardermeer, the Netherlands); within this population also two-horned tests were found. Tests 247-298 μm.
Difflugia acutissima

 

D. acutissima: Five shells from the same sample; the fourth shell is in lateral view, with biconcave sides; the fifth shell shows two horns: 225-265 µm.