Abstract
1. Clones of Daphnia longispina (O.F.M.), collected from ponds with different levels of predation, were monitored using video techniques in order to test the effects of temperature and visual cues on vertical migration behaviour.2. Endogenous rhythms were found to have a part in the control of vertical migration in some clones but responses were highly variable.3. Low temperature caused a marked increase in the amplitude of vertical migration in D. longispina, consistent with field studies.4. Clones from ponds with fish predators had larger vertical migration amplitudes than clones from ponds with no fish, providing further evidence for the genetic basis of this mechanism.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have