Physiology and Biochemistry
A recent energetics study found that Sepia apama are primarily diurnal and have a small home range (90-550 meters) over short recording periods. They are able to channel most of their energy directly into growth because they spend 95% of the day resting, suggesting bioenergetics more like that of an octopus than a squid. Very little time is spent foraging (3.7% during the day and 2.1% during the night), most of their time is spent resting and hiding in crevices from predators. The exception to this behavioral routine is the mass spawning aggregation, where cuttlefish are far more active during the days or weeks that they spend there.
References
Aitken, J. P., R. K. O'Dor and G. D. Jackson. 2005. The secret life of the giant Australian cuttlefish Sepia apama (Cephalopoda): Behaviour and energetics in nature revealed through radio acoustic positioning and telemetry (RAPT). J Exp Mar Biol Ecol 320: 77-91