ROW: Laboratory Studies of Facultative Anaerobic Benthic Foraminifera

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Foraminifera are protozoans which are generally thought to be obligate aerobes although a wide variety of evidence suggests that certain benthic forms are facultative anaerobes. This research planning projects objectives are to (1) develop a rapid, non terminal screening procedure to distinguish living from dead individuals, (2) characterize formainiferal ultrastructure after exposure to extended periods of anoxia or low oxygen conditions, and (3) establish the postmortem ultrastructural degradation sequence of foraminifers. The screening procedure will employ flourogenic substrates which will fluoresce within living specimens but which are undetectable by fluorescence microscopy in dead specimens. The ultrastructure of specimens exposed to anoxic or low oxygen condition for time periods of weeks to months will be examined with high voltage electron microscopy (HVEM). The use of HVEM permits rapid examination of a significant sample size since observed section are about 10 times thicker than those for conventional electron microscopy. In order to investigate postmortem ultrastructural changes, foraminifera will be irradiated with ultraviolet light in a dose sufficient to induce necrosis. These specimens will be examined with HVEM to assess changes over time. The results of this project will provide the foundation for future investigations concerning the physiological ecology of foraminifera inhabiting anoxic environments.