ISSN:
1432-1351
Keywords:
Paramecium multimicronucleatum
;
Axenic culture
;
Swimming behavior
;
Zeitgeber time
;
Circadian rhythm
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Abstract A unicellular organism, Paramecium, exhibits circadian rhythm activities in many physiological phenomena, i.e., mating reactivity, photoaccumulation in Paramecium bursaria and mating type reversals in Paramecium multimicronucleatum. In this study, we used an image-processing system to analyze swimming activity in a population of Paramecium multimicronucleatum cultured axenically under 12 h-light/12 h-dark cycles (LD 12∶12). Swimming behavior was recorded both under LD 12∶12 and constant darkness and images tracing the tracks of Paramecium were produced every 4 min. Swimming activity was represented by the occupied area by the tracks relative to the total observed area. It is high during daytime and low at night and exhibits a freerunning rhythm in constant darkness. Furthermore, criteria for two major components of swimming behavior, straight and circle swimming, were established and analyzed. The results indicate that swimming behavior alters depending on the time of day: straight swimming increased during the day and circling was dominant around dusk both under LD 12∶12 and constant darkness.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00216129
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