Netzelia corona – Microworld

Netzelia corona with three horns or spines

Netzelia corona (Wallich, 1864) Gooma et al., 2017
Syn.: Protocucurbitella coroniformis Gauthier-Lièvre & Thomas, 1960

Diagnosis: Shell spherical to sub‑spherical. The shell wall is composed of mineral grains (including quartz) and diatom frustules, agglutinated by an organic cement. The shell is ornamented with conical, hollow spines situated in the posterior third. The aperture is circular and surrounded by a variable number of inward‑oriented, angular crenulations (tooth‑like structures).

Dimensions: Leidy (1879): 140-320 µm; Penard (1902): 200-250 µm; Awerintzew: 180-310 µm; Cash: 180-230 µm; Hoogenraad & De Groot (1940): 155-200 µm; Lahr & Lopes: 80-380 µm ; Siemensma (www.arcella.nl, 2025): 105-193 µm, mean 156 µm.

Ecology: Freshwater; occurring in various water types, in sediment, among Sphagnum, and on aquatic plants. Often very common. The species has also been recorded from icefield lakes at high elevations (Monti 1906).

Remarks: Shells ornamented with tuberculate structures similar to those of Netzelia tuberculata have been observed by Vucetich (1973) and Siemensma (2013, www.arcella.nl). The number of conical spines in Dutch specimens is typically 4–6.

Netzelia corona with some spines and a number of teeth

N. corona , aperture with a number of teeth

Shell, dorsal and apertural view

Small spine, 33 µm long and spine with a mineral grain in the opening

Drawing: Penard, in Faune Rhizopodique du Bassin du Léman, 1902

Aperture with 12 denticulate lobes.

Each lobe is a hollow structure at the outer most part.

Shell with tubercular structure

Shell with tubercular structure – stacked image

Shell with crenulate structure, drawing Vucetich, 1973.

Netzelia corona; collection of individuals to show the variation in size and form; in number, length and shape of the spines, and the like. All drawn to the same scale. In: Jennings, 1916.

Ferry Siemensma, created February 23, 2019; last modified July 21, 2026