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Peter A. Siver 《Journal of Paleolimnology》1991,5(1):11-17
The stomatocyst of Mallomanas acaroides v. muskokana is described based on observations made from both live populations and surface sediment remains. The cyst is slightly ovate in shape, covered with evenly spaced, ornamented spines and has a short cylindrical collar with a variable apex and internal annulus surrounding the pore. The spines have a thickened base, a cylindrical middle section and a flattened apex with a ring of finger-like projections. Several immature stages of development are described and the stomatocyst is compared to those described for phylogenetically similar species. Complementary investigations of stomatocysts from both living (planktonic) and sediment collections can greatly facilitate the identification of stomatocyst morphotypes.This is the second in a series of four papers published in this dedicated issue entitled Application of Chrysophyte Stomatocysts in Paleolimnology. Dr. C.D. Sandgren served as guest editor for these papers. 相似文献
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The chrysophycean stomatocyst flora from the sediments of Upper Wallface Pond, a recently acidified Adirondack lake, was described according to the guidelines of the International Statospore Working Group. Sixty-six morphotypes were distinguished, using scanning electron microscopy. Twenty-eight of these cysts were distinguishable using the light microscope (LM), whereas 30 required grouping into 11 collective categories from LM identification, and 7 could not be identified using LM. None of our morphotypes could be linked definitively to the living chrysophyte species that produced them. Stratigraphic analysis showed that a marked change in the cyst assemblage occurred in the 1930's. Previous paleoecological studies inferred a pronouced pH decline at this time. Redundancy analysis of our data showed that diatom-inferred pH explained a significant amount of variation (Monte Carlo permutation test; p=0.01). This suggests that pH influences chrysophyte populations, and that stomatocysts could eventually be used to reconstruct pH and other variables.This is the fourth in a series of four papers published in this dedicated issue entitled Application of Chrysophyte Stomatocysts in Paleolimnology. Dr. C. D. Sandgren served as guest editor for these papers. 相似文献