La Reponse aux Couleurs chez Dicentrarchus labrax (Moronidae), Place en Situation de <<Self-feeding>>, et de Choix Multiple <B>La Reponse aux Couleurs chez Dicentrarchus labrax (Moronidae), Place en Situation de <<Self-feeding>>, et de Choix Multiple</B><P> </B><B>Response to Colours in </B><I><B>Dicentrarchus</B></I><B> </B><I><B>labrax</B></I><B> (Moronidae), in a Self-Feeding and Multiple Choice Condition<P> M. KENTOURI(1), M. AN'THOUARD(2) & P. DIVANACH(3)</B><I><P> (1) Departement de Biologie, Universite de Crete, Avenue Cnossos, GR-710 03 Iraklion, Crete, Grece<BR> (2) Laboratoire de Psychophysiologie, Universite Louis Pasteur, 7 rue de l'Universite, F-67000 Strasbourg, France.<BR> (3) Institut de Biologie Marine de Crete, Region portuaire, P.O.Box 2214, GR-71003 Iraklion, Crete, Grece.</I><B><P> Key words:</B> Feeding activity, colour perception, instrumental<B> </B>learning, <I>Dicentrarchus</I> <I>labrax</I>, self-feeding.<B><P> Abstract </B><P> A population of sea-bass, housed under semi-natural and self-feeding conditions, was presented with six different coloured levers. Their choices tended to favour more colour-contrasted levers and were greatly affected by environmental conditions such as stress factors, circadian period, season, and thermal fluctuations. A correlation was observed between increases in instrumental activity, indicating an increase in energetic requirements and a widening of choices in the exploitation of the coloured levers.<BR> Consequences of these behaviours were considered in relation to predator pressure that the fish imposes on potential prey populations in the natural environment, and in relation to the initiation of feeding activity when the fish are maintained in captivity and under self-feeding conditions.<P> P.S.Z.N. 1: Marine Ecology, 14 (3): 259-274 (1993)<P>