world of amoeboid organisms

Menu
Pterocystis veliformis
From Siemensma, 1991

Pterocystis veliformis (Dürrschmidt, 1987) Siemensma, 1991

Diagnosis: Periplast, 10—20 µm in diameter (measurement based on whole mount), with two types of scales; details of protoplast unknown. The spine scales are reminis­cent of a sail. The shaft is reduced to a short hollow rib. The lateral wings are continued along the whole length of the shaft reaching the maximum breadth in the lower 3rd of the scale. From here towards the proximal end they are closely anchylosed with the basal wing and form a short patternless stalk, sometimes only present as a concave depression around the proximal shaft end. The lateral wings are ornamented with thin, delicate ribs, which run transverselly or obliquely from the shaft to the outer margin. Ribs are also present on the front part but here they run inwards from the outer margin.

Plate scales are small, 0.9—1.3 x 0.6—0.8 µm, ovoid or, more rarely, elliptical. They are patternless except for an axial thickening which is slightly shifted to the smaller pole of the plate scale, and a narrow peripheral rim. As indicated by SEM micrograph they are not even but with distinctly concave middle parts, elevated submarginal parts and slightly inflexed margins.

Distribution: Chile, Canada.

Recent posts

Spiculophrys

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 »

Kinetocyst

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 »

Yogsothoth carteri

Yogsothoth carteri, after Shishkin and Zlatogursky, 2018 Yogsothoth carteri Shishkin and Zlatogursky, 2018 Diagnosis: Individual cells in a colony have a diameter of 9.7-15.2 µm;

Read More »