The Vertical Migration Behaviour of Estuarine Plankton

Abstract

A series of investigations on the vertical migration behaviour of estuarine zooplankton have been carried out in recent years. Several of these investigations have been carried out in collaboration with other zoologists and the detailed findings are being published separately. The work is reviewed here and an attempt is made to draw some general conclusions regarding the behaviour patterns observed. Attention is concentrated particularly on the behaviour of the copepod Pseudodiaptomus, Aspects investigated include behaviour in the field under natural conditions, light reactions and swimming speeds in the laboratory, reactions to layers of low salinity water, the role of endogenous rhythm in this behaviour and the significance of these behaviour patterns to the organisms.