Ref ID : 7745
Colin G. Ogden; The Flexible Shell of the Freshwater Amoeba Microchlamys patella (Claparede & Lachmann, 1859) (Rhizopoda: Arcellinida). Protistologica XX(1):141-152, 1985
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Notes
Observations on individual live animals has revealed information on the action of shell folding in Microchlamys patella (Claparede & Lachmann, 1859). Such movement seen by interference microscopy appears to be controlled by small cytoplasmic extensions acting on the shell margin. Other cytoplasmic activity includes a creeping movement on the substrate, with no apparent pseudopods, and the extrusion of up to three large lobose pseudopods when the animal is free-floating. The cytoplasm is contained in a membranous sac attached to the shell wall at intervals and has a central aperture. Detail of the disc-like shell revealed by both scanning and transmission electron microscopy shows that it is composed of a single layer of units arranged in a honeycomb pattern. Each unit has a small basal opening into the next unit which is considered to be related, in some way, to the mechanics of folding. The use of argon ions in a fast atom beam to etch the surface and reveal the inner walls was unsuccessful, when compared with results from fractured and sectioned specimens. The systematic position of the genus is considered in relation to the new information presented in this report.