Effects of Salt Concentration and Bacteria on Encystment Induction in Ciliated Protozoan Colpoda sp.

Masahito Yamaoka ； Tomoko Watoh ； Tatsuomi Matsuoka

《Acta Protozoologica》 43卷2期 (2004/06) Pp. 93-98

並列摘要

The promoting or suppressing elements for cyst formation (encystment) of Colpoda sp. was examined. Encystment was promoted by an increase in concentration of ions such as Ca(superscript 2+), Na(superscript +) and K(superscript +) contained in the surrounding medium, which may be detected by ciliates as an environmental signal for forthcoming desiccation, and was suppressed by the presence of bacteria in the surrounding media. When the surrounding media contained both low concentrations (1 mM) of salts and bacteria (107 cells/ml), encystment triggered by cations was completely canceled. However, a gradual increase up to finally 8 mM in salt concentration accomplished by a natural evaporation of the surrounding saline solutions invalidated the encystment-suppression effect by bacteria.

並列關鍵字

Colpoda ； encystment ； environmental signals ； desiccation