Many vertebrate and several invertebrate animals are known to sleep. In general, acute sleep deprivation can affect the formation and retrieval of memories and can lead to a state of prolonged sleeping known as recovery or rebound sleep. Another feature of sleep, only observed in birds and mammals, is the rapid eye movement or REM stage. Sleep has only been studied in a few marine invertebrates: an octopus (Octopus vulgaris) and two cuttlefish (Sepia officinalis and Sepia pharoanis). Recent work suggests that cuttlefish experience rebound sleep and REM states. My work will expand on this research by observing the effects of longer periods (72 hours) of sleep deprivation on rebound sleep, REM states, and memory formation and retention in Sepia officinalis. Cuttlefish will be allowed to learn a maze prior to sleep deprivation and then tested for retention of these memories following acute sleep deprivation. Performance will be compared to non-deprived individuals. The occurrence of REM-like states in cuttlefish is remarkable as they are very distantly related to birds and mammals and therefore may have independently evolved similarities in sleep. Incorporating marine invertebrates, cephalopods specifically, in sleep research can contribute greatly to our understanding of the importance and functions of sleep.