Crustacean Circadian Research

Heart Rate and Locomotion in Lobster: The Effect of Time of Day
 

Fig 2: Experiment 1 - The effects of time of day on average heart rate (left axis) and locomotor activity (right axis) of lobsters during LD. Top curve-heart rate; bottom curve-locomotor activity. Values represent cumulative five-minute interval averages for all six lobsters over a ten-day LD period. During D (black bar) both activities are clearly higher than during L (white bars). Note that locomotor activity increases in apparent anticipation of the onset of darkness while heart rate does not.