Octopuses (Octopus bimaculoides) and cuttleWshes (Sepia pharaonis, S. oYcinalis) can conditionally discriminate

In complex navigation using landmarks, an animal must discriminate between potential cues and show context (condition) sensitivity. Such conditional discrimination is considered a form of complex learning and has been associated primarily with vertebrates. We tested the hypothesis that octopuses and cuttleWsh are capable of conditional discrimination. Subjects were trained in two maze conWgurations (the conditions) in which they were required to select one of two particular escape routes within each maze (the discrimination). Conditional discrimination could be demonstrated by selecting the correct escape route in each maze. Six of ten mud-Xat octopuses (Octopus bimaculoides), 6 of 13 pharaoh cuttleWsh (Sepia pharaonis), and one of four common cuttleWsh (S. oYcinalis) demonstrated conditional discrimination by successfully solving both mazes. These experiments demonstrate that cephalopods are capable of conditional discrimination and extend the limits of invertebrate complex learning.