world of amoeboid organisms

Menu
Centropyxis

Family Centropyxidae Jung, 1942

Diagnosis: Lobose testate amoebae with shell of granular organic material, dorsally with more or less mineral particles or diatoms, ventrally smooth or with much smaller grains; dorsal surface rounded, ventral side flat to concave, with a ventral aperture, which may be circular to uneven, but displaced towards one end; shell may be flattened at the apertural end; at the posterior end or all around the periphery some spines may be present.

Type genus: Centropyxis.

Key to the genera
1
Aperture surrounded by a funnel-shaped construction
Conicocassis
Aperture not surrounded by a funnel-shaped construction
2
2
Aperture invaginated
3
Aperture not invaginated
Proplagiopyxis
3
Anterior walls of the aperture are not attach to the dorsal side
Anterior walls of the aperture are attached to the dorsal side by one or more struts
Armipyxis **)

*) For the time being I will consider all species with internal struts as belonging to this genus.
**) The genus Armipyxis was created by Dekhtiar (2009) to accommodate all species with internal struts. In my opinion that is not correct, because if you use this morphological character, you leave strut-less species in the Centropyxis group that are morphologically much closer to species with internal struts than many other Centropyxis species.

Centropyxis discoides
Test of Centropyxis discoides, see detail below
Centropyxis discoides
The test consists of an organic layer of granular structure with embedded xenosomes, here several kind of diatoms, some with remnants of the chloroplast still present.
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 »