Ref ID : 4725
Monika Durrschmidt; An Electron Microscopical Study on Freshwater Heliozoa (Genus Acanthocystis, Centrohelidia) from Chile, New Zealand, Malaysia and Sri Lanka. III. Arch.Protistenk 133:49-80, 1987
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This is the third report on the occurrence and taxonomy of freshwater species of the Centrohelidian (Heliozoa) genus Acanthocystis in Chile, New Zealand, Malaysia and Sri Lanka, based on the use of electron microscopy of whole mounts. Twenty one taxa are included here, 18 of which are new: A. erinaceoides Petersen & Hansen ssp. sculpta, A. erinaceoides ssp. undulata, A. kilianii, A. tropica, A. tropica spp. paucistriata, A. paliformis, A. pyriformis, A. foliacea Durrschmidt ssp. elongata, A. foliacea ssp. truncata, A. rasilis, A. pteromorphos, A. ovata, A. plumosa, A. veliformis, A. umbraculiformis, A. flabellata, A. flabellata ssp. novae-zelandiae and A. latimarginalis. A. pinnata Nicholls is a new find for Chile, New Zealand and Sri Lanka. A. pulchra has been found in New Zealand for the first time, and A. striata is a new record from Chile and New Zealand. The currently known 54 EM-studied taxa of Acanthocystis may be divided into two sections on the basis of the morphology of their plate scales. Section I includes species with a broad peripheral rim on the plate scales (A. striata Nicholls, A. latimarginalis), while section II comprises those with plate scale with or without a narrow rim. The Acanthocystis species of section II have been arranged in 6 different groups and 8 subgroups according to similarities in spine scale structure. Possible evolution in scale structure in Acanthocystis and interrelationships within the genus are discussed.