world of amoeboid organisms

Menu
Raphidiophrys minuta
From Siemensma, 1991

Raphidiophrys minuta Nicholls, 1985

Diagnosis: Cells 10-15 µm in diameter (excluding scales). Scale layer 2-5 pm thick and noticeably clustered along beaded axopodia up to 50 µm long. Scales circular, to circular-ovate in outline, 2-6 µm in diameter. Scales are patterned with alternately long and short, wavy, radially dis­posed ribs; the long ones are 2 to 4 times longer than the short ones and extend from the scale margin to the centre of the scale. Scales lack a folded rim.

Ecology: Collected in the plankton of West Twin Lake, Ontario, Canada, 1979.

Remarks: Raphidiophrys minuta scales differ from those of other species with similar ornamentation by their lack of a marginal folded rim. Also the radial ribs originate from the scale centre, not from a median axis as in R. intermedia, R. elegans, and R. orbicularis.

I found this very small heliozoan in a sample from the Laegieskamp, the Netherlands (2016). It radiates some stiff axopodia each with 3-4 prominent extrusomes. It might be R. minuta.
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 »