The protozoan Paramecium caudatum was examined under normal conditions versus aside a switched-on GSM telephone (900 MHz; 2 Watts). Exposed individuals moved more slowly and more sinuously than usual. Their physiology was affected: they became broader, their cytopharynx appeared broader, their pulse vesicles had difficult in expelling their content outside the cell, their cilia less efficiently...

Ciliated protists often form symbioses with many diverse microorganisms. In particular, symbiotic associations between ciliates and green algae, as well as between ciliates and intracellular bacteria, are rather wide-spread in nature. In this study, we describe the complex symbiotic system between a very rare ciliate, Paramecium chlorelligerum, unicellular algae inhabiting its cytoplasm, and no...

The ciliate Paramecium caudatum possesses an excitable cell membrane whose action potentials (APs) modulate the trajectory of the cell swimming through its freshwater environment. While many stimuli affect the membrane potential and trajectory, students can use current injection and extracellular ionic concentration changes to explore how APs cause reversal of the cell's motion. Students examin...

The structure of undischarged and discharged trichocysts has been examined in Paramecium caudatum, and their light-microscopic appearance compared with their fine-structural organization. In living specimens undischarged trichocysts appear to be of a single type with a unimodal variation in length about a mean of 37 fim. When fixed for electron microscopy or compressed beneath a coverslip many ...

1. We used the freshwater alga Chlorella NC64A (Division Chlorophyta) and its virus Paramecium bursaria Chlorella virus-1 (PBCV-1) as a model system to test for potential stoichiometric constraints on a virus–host interaction. 2. Media phosphorus concentrations were manipulated to create Chlorella NC64A host cells with low (91 ± 23) or high (453 ± 246) C : P ratio. In contrast, the C : P ratio ...