world of amoeboid organisms

Pterocystis fortesca
R. fortesca – from Siemensma, 1991

Raineriophrys fortesca (Nicholls, 1983) Mikrjukov, 1999

Diagnosis: Cells with a diameter of 15-20 μm, periplast represented by lamellar scales and radial spicules of one type. Spicules with a length of 10-16 μm, apices bear 2-3 teeth. Basal plate connected with proximal part of the stem between wings forming a triangular lobe. Lamellar scales elliptical, with a size of 3.0-3.8 x 1.8-2.3 µm, have a poorly pronounced medial thickening.

Ecology: Distributed in fresh waters of Germany, The Netherlands, Russia, Canada, Chile, Argentina, Japan, Australia, and brackish waters of the Gulf of Finland of the Baltic Sea.

Recent posts

Polychaos spec.

Polychaos spec. Polychaos spec. Diagnosis: Large amoeba with an irregular more or less polypodial shape during slow locomotion; uroid finely papillated, usually very large fasciculate

Read More »


Genus Spiculophrys Zlatogursky, 2016 Diagnosis: Centrohelids lacking silica scales but with numerous thin, pointed organic (without any traces of silica) scales tapering towards acute apices. 18S

Read More »

Acanthocystis drakena

From Zlatogursky, 2016 Acanthocystis drakena Zlatogursky, 2016 Diagnosis: Cells are 21.1-30.5 µm (ca. 26.7) in diameter. Cell is covered with oval plate-scales having a margin

Read More »

Choanocystis symna

From Zlatogursky, 2014 Choanocystis symna Zlatogursky, 2014 Diagnosis: Cell body ca. 6.7 µm in diameter. Axopodia three–five times longer than a cell diameter. Plate-scales dumbbell-shaped

Read More »

Acanthocystis costata

From Zlatogursky, 2014 Acanthocystis costata Zlatogursky, 2014 Diagnosis: Cell body ca 9.5 µm in diameter. Axopodia 2–3 times longer than cell diameter. Length of spine-scales

Read More »


Left: ultra-structure of a kinetocyst of Raphidiophrys contractilis); right: two kinetocysts in an axopodium. Kinetocysts In centrohelid heliozoa, extrusomes are called kinetocysts, and are present

Read More »