world of amoeboid organisms

Menu
Raphidiophrys heterophryoidea
Raphidiophrys heterophryoidea, after Zlatogursky (2012)

Raphidiophrys heterophryoidea Zlatogursky, 2012

Diagnosis: Cell body spherical. Periplast composed of both radial spicules and tangential plate scales. Scales are siliceous, elliptical, with hollow inflected margin. The material forming the upper plate of the scale is present in the central part only. Spicules organic, spindle-shaped, smooth, radially arranged. Septa between two plates of a scale sometimes branching or terminating before reaching the central part of a scale.

Dimensions: cell body ca. 24 µm in diameter, plate scales 4-7 X 2-6 µm, length:width ratio 1.1-1.9; spicules 10-26 µm long.

Ecology: Fresh water; Sphagnum bog and lake sediments in Russia.

Remarks: Raphidiophrys heterophryoidea has two unique features within this genus, i.e. spindle-shaped spicules and branching septa. The plate scales of the new species cannot be attributed to any known scale type. They are similar in size to the scales of R. minuta Nicholls and Dürrschmidt, 1985, but, contrary to the latter species, not radially symmetrical (Nicholls and Dürrschmidt 1985). They are oval and not elongated, as in R. capitata Siemensma and Roijackers, 1988, and R. viridis Archer, 1867. They are similar to the scales of R. ovalis (Dürrschmidt, 1985) Siemensma and Roijackers, 1988 with regard to the partial absence of the upper plate (as seen under SEM), but have a different shape, size and length/width ratio (Siemensma and Roijackers 1988)

Raphidiophrys heterophryoidea
Raphidiophrys heterophryoidea, silica scales (shown in red); organic spicules (shown in blue). – Photomicrograph: Vasily Zlatogursky
Raphidiophrys heterophryoidea
Raphidiophrys heterophryoidea, siliceous cyst scales. Mosaic scales of outer layer (shown in light-green) and overlapping scales of inner layer (shown in dark-green) – Photomicrograph: Vasily Zlatogursky
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 »