| Summary: | 碩士 === 國立東華大學 === 海洋生物多樣性及演化研究所 === 98 === The cell walls of zooxanthellae are surrounded by several layers of membrane and
cannot be directly observed. The external morphology of all life stages and the
abundance of different stages during culture is not clear for Symbiodinium. In this study,
we tried to strip off the membranes using different concentrations of the detergent Triton
X-100 to determine the surface ultrastructure. We also determined the percentage of
difference life stages at different time. First, we compared the effect of different
concentrations (0, 1, 10, 20%) of Triton X-100 at different time length (0.5, 1, 2, 24h)
on freshly isolated zooxanthellae from sea anemone (Aiptasia pulchella). Furthermore,
we used the optimal concentration and time length to strip off the membranes of
zooxanthellae in culture in order to observe the external portion of the algae. The results
showed that using 10% concentrations of Triton X-100 and shaking for 30 minutes
could strip more membrane layers without damaging the cell walls. Using 1%
concentrations at a short time could strip off only a few membranes, while in other
concentrations and with increased treatment time, cavity, fissure and crease were
observed on the surface of the algae. The life stages of zooxanthellae in culture can be
divided into vegetative phase, 2- and 4-division, zoosporangia and zoospore stages. No
identifiable characteristics on the surface can be observed when each stage was treated
with 10% Triton for 30 minutes. The proportion of each stage in the culture were
significantly different among different stages, with the vegetative stage significantly
higher than other stages. No pattern of change among stages was observed, however the
proportion of zoospore stage was significantly higher at the beginning of the culture
period.
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