title: Short-range homing in a site-specific fish: search and directed movements.
abstract: Sedentary and territorial rockfish of the genus Sebastes exhibit distinctive homing ability and can travel back to an original location after displacements of metres or even kilometres. However, little is known about the behavioural and sensory mechanisms involved in homing. Although our previous study demonstrated that nocturnal black rockfish Sebastes cheni predominantly use their olfactory sense for homing from an unfamiliar area, the possibility of using landmarks in a familiar area cannot be discounted; i.e. site-specific fish are likely to use three-dimensional spatial memory for navigation and orientation. Using high-resolution acoustic telemetry, we investigated whether S. cheni exhibit distinctive homing paths. Results show that all of the eight rockfish increased their effort within a small area of an unfamiliar region around the release site just after displacement, suggesting that the rockfish probably searched for the homeward direction. The rockfish showed the search movement in the upstream and/or downstream direction, which did not lead home. Finally, after returning to their familiar area, the rockfish exhibited more directed movements with faster speeds at a shallower depth, which was similar to the depth utilised in daily life as well as that of the fish capture.
authors: Graduate School of Informatics, Kyoto University, Kyoto 606-8501, Japan. mitamura@bre.soc.i.kyoto-u.ac.jp
authors: Hiromichi
authors: H
authors: Mitamura
authors: Keiichi
authors: K
authors: Uchida
authors: Yoshinori
authors: Y
authors: Miyamoto
authors: Toshiharu
authors: T
authors: Kakihara
authors: Aki
authors: A
authors: Miyagi
authors: Yuuki
authors: Y
authors: Kawabata
authors: Kotaro
authors: K
authors: Ichikawa
authors: Nobuaki
authors: N
authors: Arai
mesh_terms: D000818:Animals; D061006:Bays; D017753:Ecosystem; D005399:Fishes / Q000502:physiology*; D006702:Homing Behavior / Q000502:physiology*; D007564:Japan; D009068:Movement / Q000502:physiology*; D009949:Orientation / Q000502:physiology*; D013550:Swimming / Q000502:physiology; D013997:Time Factors; D014872:Water Movements