Daniela Meisel´s PhD research is funded by a grant of the Austrian Academy of Sciences. Timekeeping is an extremely important issue for animals, especially those which are known to "live fast and die young" such as octopus. Since little is known about the way octopuses use time, the purpose of this project is to investigate how these animals organize their lives and the time cues that synchronize their behavior, activity, and sleep with the cyclic changes in their environment. The four basic questions I want to examine are: (1) To what extent does light act as a time cue for the activity and behavior of O. vulgaris? (2) To what extent does light act as a time cue for the activity and behavior of O. macropus? (3) Do O. vulgaris and O. macropus produce temporal spacing of their activity patterns? (4) Can sleep in O. vulgaris be defined by associated component behaviors? To investigate these questions a series of controlled experiments will be conducted.