title: Eye as a key element of conspecific image eliciting lateralized response in fish.
abstract: Visual lateralization in different aspects of social behaviour has been found for numerous species of vertebrates ranging from fish to mammals. For inspection of a shoal mate, many fishes show a left eye-right hemisphere preference. Here, we tested the hypothesis that in fish, there is a key cue in the conspecific appearance, which elicits lateralized response to the whole image of the conspecific. In a series of eight experiments, we explored eye preferences in cryptic-coloured Amur sleeper, Perccottus glenii, fry. Fish displayed left-eye preferences at the population level for inspection of a group of conspecifics, their own mirror image, and a motionless flat model of a conspecific. In contrast, no population bias was found for scrutinizing an empty environment or a moving cylinder. When fry were showed a model of a conspecific in a lateral view with the eye displaced from the head to the tail, they again showed a significant preference for left-eye use. On the other hand, 'eyeless' conspecific model elicited no lateralized viewing in fry. Finally, the left-eye preference was revealed for scrutiny of the image of a conspecific eye alone. We argue that in Amur sleeper fry, eye is the element of the conspecific image, which can serve as a 'key' for the initiation of lateralized social response. This key element may serve as a trigger for the rapid recognition of conspecifics in the left eye-right hemisphere system. Possible causes and advantages of lateralized perception of social stimuli and their key elements are discussed in the context of current theories of brain lateralization.
authors.affiliation: Department of Vertebrate Zoology, Faculty of Biology and Soil Sciences, Saint-Petersburg State University, Universitetskaya nab., 7/9, 199034, St. Petersburg, Russia.
authors.forename: Karina A
authors.initials: KA
authors.lastname: Karenina
authors.forename: Andrey N
authors.initials: AN
authors.lastname: Giljov
authors.forename: Yegor B
authors.initials: YB
authors.lastname: Malashichev
mesh_terms: D000818:Animals; D007839:Functional Laterality / Q000502:physiology; D009799:Ocular Physiological Phenomena; D010473:Perciformes / Q000502:physiology; D010775:Photic Stimulation; D012919:Social Behavior