Paraquadrula irregularis, 31 µm – stacked image
Paraquadrula irregularis (Wallich, 1863)
Diagnosis: Shell transparent, broad oval, slightly compressed, composed of secreted quadratic or rectangular calcite plates in rows, sheet-like cement; nucleus vesicular.
Dimensions: Literature: 25-48 µm; my measurements: length 29-44 µm.
Ecology: fresh water and mosses; I found this species in a large deep lake, the Spiegelplas in The Netherlands, and in a sphagnum bog in Tirol, Austria. In 2014 I found a large number of specimens in dry mosses growing on the roof terrace of the Freie Universität Berlin. Hoogenraad & De Groot (1940) found this species in sediments of eutrophic calcite rich water.
Paraquadrula irregularis 40 µm – Photomicrograph Eckhard Voelcker
Two shells from dry mosses on a roof terrace in Berlin
Paraquadrula irregularis 43-44 µm – dry mosses, roof terrace Freie UniversitÃ¤t Berlin, Germany
Paraquadrula irregularis 43-44 µm – dry mosses, roof terrace Freie Universität Berlin, Germany
Paraquadrula irregularis from a sample from Tirol. Left: DIC and polarized light, right: DIC.
Paraquadrula irregularis in polarized light – Photomicrograph Angie Opitz, Austria.
Paraquadrula irregularis, 31 µm, lateral view.
Paraquadrula irregularis, 29 µm, from the same sample as above.
Paraquadrula irregularis, dry moss, Berlin