title: Effects of Visual Cues of a Moving Model Predator on Body Patterns in Cuttlefish Sepia pharaonis.
abstract: We examined the effects of predator-prey distance (PPD) and trajectory of the predator on the body patterns that the pharaoh cuttlefish, Sepia pharaonis, shows in response to a predator. A model predator moving in three different trajectories was presented to the cuttlefish: T1, approached the cuttlefish but bypassed above; T2, approached directly toward the cuttlefish; T3, bypassed the cuttlefish both vertically and horizontally. We divided the body patterns that the cuttlefish expressed into seven categories, i.e., "uniform light", "disruptive", "center circle", "dark square", "vertical stripe", "all dark" and "eyespots". In T1, the number of individuals that showed "dark square" increased as the model approached the cuttlefish, whereas the number of individuals that showed "disruptive" decreased. In T2, the number of individuals that showed "all dark" and "eyespots" increased as the model approached the cuttlefish. In T3, the number of individuals that showed "dark square" and "vertical stripe" increased as the model approached the cuttlefish, and it tended to decrease as the model receded from the cuttlefish. These results demonstrate that S. pharaonis changes its body patterns according to PPD and the trajectory of the predator, which would affect predation risk and/or predator perception.
authors.affiliation: 1 Department of Zoology, Graduate School of Science, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan.
authors.forename: Kohei
authors.initials: K
authors.lastname: Okamoto
authors.affiliation: 1 Department of Zoology, Graduate School of Science, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Mori
authors.affiliation: 2 Department of Chemistry, Biology and Marine Science, Faculty of Science, University of the Ryukyus, 1 Senbaru, Nishihara, Okinawa 903-0213, Japan.
authors.forename: Yuzuru
authors.initials: Y
authors.lastname: Ikeda
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D015350:Contrast Sensitivity; D004924:Escape Reaction / Q000502:physiology*; D005399:Fishes; D049833:Sepia / Q000502:physiology*; D014796:Visual Perception
keywords: body pattern; cuttlefish; predator trajectory; predator-prey distance; primary defense