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Vertical Diurnal Migration and Endogenous Rhythmicity
J. T. Enright and W. M. Hamner
New Series, Vol. 157, No. 3791 (Aug. 25, 1967), pp. 937-941
Published by: American Association for the Advancement of Science
Stable URL: http://www.jstor.org/stable/1722121
Page Count: 5
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Experimental studies of mixed populations of marine zooplankton have demonstrated that internal rhythms, synchronized by a light-dark cycle, are of dominant importance for the vertical migration of several species of crustaceans. For certain other organisms, the vertical migrations observed in the experiments can be accounted for as direct responses to light intensity only. Performances intermediate between these extremes were also observed, as well as behavior based on biological timing mechanisms that are not rhythms in the usual sense.
Science © 1967 American Association for the Advancement of Science