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Structure and Elemental Composition of the Cyst Wall of Echinosphaerium nucleofilum Barrett (Heliozoea, Actinophryida) 1
Author(s) -
PATTERSON DAVID J.,
THOMPSON DUDLEY W.
Publication year - 1981
Publication title -
the journal of protozoology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.067
H-Index - 77
eISSN - 1550-7408
pISSN - 0022-3921
DOI - 10.1111/j.1550-7408.1981.tb02831.x
Subject(s) - transmission electron microscopy , electron microscope , scanning electron microscope , layer (electronics) , optimal distinctiveness theory , ultrastructure , anatomy , cyst , materials science , crystallography , chemistry , biology , composite material , optics , pathology , nanotechnology , physics , medicine , psychology , psychotherapist
The structure of the cyst wall of the heliozoon Echinosphaerium nucleofilum has been investigated using light microscopy, scanning and transmission electron microscopy, and X‐ray microanalysis. The cyst wall is a composite structure of seven or eight layers. These are: an enveloping gelatinous layer; a layer of siliceous spheroidal bodies; an electron‐dense supporting membrane; a broad electron‐lucent zone; an electron‐dense layer; a layer of helicoidally packed material; and one or two layers with a granular appearance lying next to the plasma membrane of the encysted organism. The structure of the cyst wall closely resembles that of Actinophrys sol , confirming the close relationship of these actinophryid heliozoa while emphasizing their distinctiveness from other amoeboid protista.