Netzelia Ogden 1979

Introduction

Three species, type species N. oviformis (Cash, 1909).

Characteristics

The shell is ovoid, circular in cross-section, pseudostome lobed with a thick organic rim or a necklace made of small idiosomes. Species of Netzelia differ from lobed species of Difflugia in their ability to build their test completely from endogenous siliceous elements (idiosomes) although they can use small sand grains, diatoms or undigested algal cell walls as supplementary building material. These xenosomes are always smoothed and modified by the deposition of silica (Anderson, 1987). The idiosomes often have a nail like shape. All particles are held in position by perforated cement units and are arranged in a single layer. Usually outline regular but one species (N. tuberculata) often has protuberances to give a mulberry-like appearance. 

Ecology

References

Anderson, O. R. 1989. Some observations of feeding behavior, growth, and test particle morphology of silica-secreting testate amoeba Netzelia tuberculata (WALLICH) (Rhizopoda, Testacea) grown in laboratory culture. Arch. Protistenk., 137:211-221.

Anderson, O. R. 1990. Effects of silicate deficiency on test morphology, cytoplasmic fine structure, and growth of the testate amoeba Netzelia tuberculata (Wallich) Netzel (Rhizopoda, Testacea) grown in laboratory culture. Arch. Protistenk., 138:17-27.

Netzel, H. 1976. Die Ultrastruktur der Schale von Difflugia oviformis (Rhizopoda, Testacea). Arch. Protistenk., 118:321 329+ T. 63 70.

Ogden, C. G. 1979. Siliceous structures secreted by members of the subclass Lobosia. Bull. Br. Mus. Nat. Hist. (Zool.), 36:203-207.

Ogden, C. G. & Meisterfeld, R. 1989. The taxonomy and systematics of some species of Cucurbitella, Difflugia and Netzelia (Protozoa: Rhizopoda); with an evaluation of diagnostic characters. Europ. J. Protistol., 25:109-128.