Hough, A.R. & E. Naylor. (1992). Endogenous rhythms of circatidal swimming activity in the estuarine copepod Eurytemora affinis (Poppe). Journal of Experimental Marine Biology and Ecology. 161(1):27-32.
Endogenous rhythms of circatidal swimming activity in the estuarine copepod Eurytemora affinis (Poppe).
Journal of Experimental Marine Biology and Ecology
161(1):27-32.
Publication
Available for editors
Under constant conditions in the laboratory the estuarine copepod Eurytemora affinis (Poppe) displays an endogenous circatidal swimming rhythm. The phasing of peak endogenous activity varies with the semilunar (neap-spring) cycle and with position along the estuary. Animals collected on spring tides of increasing amplitude show peak activity during the expected flood tide, while those sampled on spring tides of decreasing amplitude or towards the limit of tidal influence display peak activity during the expected ebb tide. This is apparentlu the first report of an endogenous circatidal rhythm in a copepod, the phase-lability of which is unusual. These findings also support field observations on tidal abundances and position maintenance behaviour in this species.
