Netzelia tuberspinifera (Hu, Shen and Gong, 1997) Gomaa et al., 2017

 

Diagnosis: shell spherical to sub-spherical, mulberry-shaped,composed of fine sandgrains, muddy particles and flattish pieces of quartz. The shell surface has many protuberances similar to N.tuberculata. Shells ornamented with two to eight conical hollow spines at the upper equator region. Spineless morphotypes have been also described (Gomaa et al. 2015; Yu et al. 2014). The aperture is circular with a short collar and bordered by a variable number of tooth-like structures.

Morphology: The shell has a sub-spherical to spherical form, composed of fine sand granules, flattish pieces of quartz and muddy particles. In apertural view, the shell is circular, furnished with a variable number of conical spines, varying from 4 to 8, usually 5-6. The aperture is terminal, circular, its border denticulated to crenulated with a variable number of small, but perfectlyregular tooth-like structures, numbering from 7 to 10, usually 8-9, without any accompaniment of larger quartz grains. In lateral view, the aperture shows a short collar, and the position of the conical spines at the upper equatorial region. The surface of shell is not smooth and has many regular blunt protuberances. In other words, the shell has a mulberry-shaped appearance. However, the shell walls are even in thickness. Accordingly, internal walls of the shell are sunken). The protuberance is composed of small sand granules and flattish pieces of quartz. No cement structures were recognizable in the scanning electron microscope. The shell is yellowish to brown, the pseudopodia long, colourless and rather thin, generally 3 to 7. As the shell is opaque, cytoplasmic characters were not observed.

 

Dimensions: Test heigth 94-129 µm; test diameter 94-118µm; aperture diameter 39-64µm; collar 6-18µm.

 

Ecology: in oligotrophic lakes; in lotic and lentic environments; widespread in freshwater in the Changjiang Valley, China.

 

Literature: Yang, J., Beyens, L., Shen, Y. and Feng, W.: Redescription of Difflugia tuberspinifera Hu, Shen, Gu et Gong, 1997 (Protozoa: Rhizopoda: Arcellinida: Difflugiidae) from China - Acta Protozool. (2004) 43: 281 - 289