Possible functions of the octavolateralis system in fish schooling

Authors

  • Matz Larsson

    1. Department of Respiratory Medicine, Örebro University Hospital, SE 701 85 Örebro; The Institute of Environmental Medicine, Karolinska Institutet, Box 210, SE-171 77, Stockholm, Sweden
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    Ghoti aims to serve as a forum for stimulating and pertinent ideas. Ghoti publishes succinct commentary and opinion that addresses important areas in fish and fisheries science. Ghoti contributions will be innovative and have a perspective that may lead to fresh and productive insight of concepts, issues and research agendas. All Ghoti contributions will be selected by the editors and peer reviewed.
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    George Bernard Shaw (1856-1950), polymath, playwright, Nobel prize winner, and the most prolific letter writer in history, was an advocate of English spelling reform. He was reportedly fond of pointing out its absurdities by proving that `fish' could be spelt `ghoti'. That is: `gh' as in `rough', `o' as in `women' and `ti' as in palatial.

Matz Larsson, Department of Respiratory Medicine, Örebro University Hospital, SE-701 85 Örebro; The Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
Tel.: +46 196025596
Fax: +46 19186526
E-mail: matz.larsson@orebroll.se

Abstract

The development of the octavolateralis system in fish ancestors created the phenomenon of sensory reafference associated with the fish’s own locomotion. Particularly in fish species living and moving in groups, there is a potential to produce complex pressure waves and other water movements interfering with the octavolateralis perception of critical environmental signals. The hypothesis presented is that the development of the octavolateralis system may have initiated, or been a factor in, the evolutionary development of synchronized group locomotion, eventually leading to schooling behaviour. Theoretical models suggest that schooling may be related to a reduction in masking of environmental signals, as well as to survival mechanisms, e.g. confusion of the lateral line and electro-sensory systems of predators by overlapping pressure waves and overlapping electrical fields. The combined effects of reduced masking and predator confusion may help explain why schooling became an evolutionary success. Including pressure waves and other water movements in the model of join, stay or leave decisions might shed some light on fish shoal assortment. A model encompassing the complex effects of synchronized group locomotion on octavolateralis and electro-sensory perception of both prey and predator fish might increase the understanding of schooling behaviour.

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