Figure 4.

Locomotor activity recorded from a juvenile horseshoe crab expressing a nocturnal pattern of activity in LD, and then switching to a circatidal pattern of activity DD. Initially during LD, there is activity present during both day and night. The activity during the day becomes ‘masked’ and is reduced in amount. Note that the nocturnal bout of activity in LD transitioned into one of the apparent tidal bouts of activity in DD. During DD, there were two bouts of activity each day and they each had a different duration. Refer to Figure 1 for a detailed description of figure components.