Fig 1:Experiment 1 - Representative actograms of locomotor and heart rate activity from a lobster in LD and DD. The values are double-plotted to improve visualization of the results. Scale: HR=min-0, max-120 bpm; Loco=min-0, max-1 rpm. In LD heart rate and locomotor activites were clearly higher during D (black bars) compared to L (white bars). All lobsters (n=6) showed virtually identical patterns. When exposed to DD, the patterns of activity persisted and the periods of activity were circadian. Statistically significant free-running locomotor activity rhythms were seen in all animals exposed to DD and while significant heart rate rhythms were observed in four of six animals. There was no statistical difference (t(5)=0.8, p=0.46) detected between the periods of heart rate (24.54+/-0.48) and locomotion (24.96+/-0.55).
Time of Day (h)