world of amoeboid organisms

Menu

Acanthocystis nichollsi

 

Acanthocystis nichollsi Siemensma and Roijackers, 1988

This name was proposed for a species identified by Nicholls (1983) as Acanthocystis pectinata. Nicholls (1983) gave an emended diagnosis of A. pectinata, but his specimens differ from the original diagnosis of this species. A. pectinata is characterised by the presence of numerous short spine-scales, all of the same length (Penard 1889, 1904) and a scanty number of long spine-scales (Rainer 1968). Rainer emphasised that the presence of a very small number of long spine-scales is a specific character, which was confirmed by Siemensma (1981). The Canadian specimens deviate clearly from the European specimens in having many long spine-scales, and Nicholls (1983) observed all intermediate lengths between long and short spine-scales. Therefore, the light microscopic appearance of these specimens does not correspond well with the original description of A. pectinata nor with the emendation by Rainer (1968). The surface of the plate-scales of the Canadian specimens is smooth, whereas the specimens I observed from several localities throughout the Netherlands, and which I consider to be identical with A. pectinata, all have granulated plate-scales. In TEM, the plate-scales of A. nichollsi have radial slits, which are lacking in A. pectinata. Acanthocystis nichollsi closely resembles A. polymorpha Dürrschmidt, 1985, the plate-scales of which lack any granules or slits.

Acanthocystis nichollsi malayensis

Acanthocystis nichollsi  spp. malayensis

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 »

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 »