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Variability of the fast suction feeding process in Astatotilapia elegans (Teleostei: Cichlidae): a hypothesis of peripheral feedback control

Authors

  • Peter Aerts

    1. Zoological Institute, State University Ghent, Ledeganckstraat 35, B-9000 Ghent, Belgium
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      Laboratorium voor Morfologie en Systematiek der Dieren, Ledeganckstraat 35, B-9000 Ghent, Belgium. Peter Aerts is a senior research assistant of the Belgium National Fund for Scientific Research.


Abstract

Movement analysis of the ‘volume suction’ feeding type in Astarotilapia elegans suggests the existence of an inhibiting peripheral feedback control on the fast movements of the head parts, apparently triggered by the food items entering through the mouth aperture. As soon as the prey passes the mouth, rostral expansion of the buccopharyngeal cavity stops. On the basis of a mathematical model and physiological evidence, respectively, visual and chemical perception must probably be excluded as the initial stimulus of the feedback control. The simulation of the hydrodynamic characteristics of the suction flow at the level of the gape reveals sudden changes in the pressure and acceleration waves coupled to the moment of prey uptake. These fluctuations are premised to generate the triggering signal. The possibility of modulation entails re-evaluation of the neuro-motoric preprogamming concept.

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