title: Facial Recognition in a Group-Living Cichlid Fish.
abstract: The theoretical underpinnings of the mechanisms of sociality, e.g. territoriality, hierarchy, and reciprocity, are based on assumptions of individual recognition. While behavioural evidence suggests individual recognition is widespread, the cues that animals use to recognise individuals are established in only a handful of systems. Here, we use digital models to demonstrate that facial features are the visual cue used for individual recognition in the social fish Neolamprologus pulcher. Focal fish were exposed to digital images showing four different combinations of familiar and unfamiliar face and body colorations. Focal fish attended to digital models with unfamiliar faces longer and from a further distance to the model than to models with familiar faces. These results strongly suggest that fish can distinguish individuals accurately using facial colour patterns. Our observations also suggest that fish are able to rapidly (≤ 0.5 sec) discriminate between familiar and unfamiliar individuals, a speed of recognition comparable to primates including humans.
authors.affiliation: Laboratory of Animal Sociology, Department of Biology and Geosciences, Graduate School of Sciences, Osaka City University, Sumiyoshi, Osaka 558-8585, Japan.
authors.forename: Masanori
authors.initials: M
authors.lastname: Kohda
authors.affiliation: Laboratory of Animal Sociology, Department of Biology and Geosciences, Graduate School of Sciences, Osaka City University, Sumiyoshi, Osaka 558-8585, Japan.
authors.forename: Lyndon Alexander
authors.initials: LA
authors.lastname: Jordan
authors.affiliation: Laboratory of Animal Sociology, Department of Biology and Geosciences, Graduate School of Sciences, Osaka City University, Sumiyoshi, Osaka 558-8585, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Hotta
authors.affiliation: Laboratory of Animal Sociology, Department of Biology and Geosciences, Graduate School of Sciences, Osaka City University, Sumiyoshi, Osaka 558-8585, Japan.
authors.forename: Naoya
authors.initials: N
authors.lastname: Kosaka
authors.affiliation: Department of Biology, Tokyo Gakugei University, Koganei, Tokyo 184-8501, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Karino
authors.affiliation: Laboratory of Animal Sociology, Department of Biology and Geosciences, Graduate School of Sciences, Osaka City University, Sumiyoshi, Osaka 558-8585, Japan.
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Tanaka
authors.affiliation: Laboratory of Animal Sociology, Department of Biology and Geosciences, Graduate School of Sciences, Osaka City University, Sumiyoshi, Osaka 558-8585, Japan.
authors.forename: Masami
authors.initials: M
authors.lastname: Taniyama
authors.affiliation: Laboratory of Animal Sociology, Department of Biology and Geosciences, Graduate School of Sciences, Osaka City University, Sumiyoshi, Osaka 558-8585, Japan.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Takeyama
mesh_terms: D000349:Africa; D000374:Aggression / Q000502:physiology*; D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D023681:Cichlids / Q000502:physiology*; D003116:Color; D003463:Cues; D060106:Lakes; D008297:Male; D010364:Pattern Recognition, Visual / Q000502:physiology*; D021641:Recognition, Psychology / Q000502:physiology*; D013731:Territoriality