Variation in the naturally occurring rhythm of the estuarine amphipod, Corophium volutator
In: Journal of the Marine Biological Association of the United Kingdom. Cambridge University Press/Marine Biological Association of the United Kingdom: Cambridge. ISSN 0025-3154; e-ISSN 1469-7769, more
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| Keywords |
Activity patterns
Aquatic organisms > Estuarine organisms
Biological phenomena > Biological rhythms
Endogenous rhythms
Corophium volutator (Pallas, 1766) [WoRMS]; Malacostraca [WoRMS]
Brackish water |
| Authors | | Top |
- Holmström, W.F.
- Morgan, E.
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| Abstract |
The endogenous activity rhythm of the estuarine amphipod Corophium volutator has been studied by direct observation and with the use of time lapse photography. The rhythm persists under constant conditions having a free running period of between 12 and 13 h, and with activity maxima occurring during the early ebb. Freshly collected animals show a rhythm which is modulated on a semi-lunar basis, the activity maxima being attenuated during the neap tide periods, and the rhythm has also been found to vary in definition throughout the year. The activity pattern is most clearly denned in early summer and autumn, the population becoming arrhythmic during the winter months. The rhythm is relatively unaffected by the ambient light intensity and temperature of the recording conditions, and is evident in all post-natal stages of development. The possibility of mutual entrainment is discussed. |
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