Régime alimentaire des alevins de Gardons ( Rutilus rutilus (L.)) dans un port du lac Léman. Comparison avec la nourriture disponible.

In order to determine the food preferences of young roach, gut contents of roach fry ( Rutilus rutilus (L.)) were compared with the evolution of the zooplankton community in a littoral area of Lake Geneva during June and July 1985. The food of roach fry up the age of 30 d (10-15 mm standard length) was mainly small Rotifers with some Chronomid larvae. Thereafter, Chironomid larvae constitute the major part of the diet until the fry leave the littoral zone at the age of about 45 d (15-23 mm). The relevance of classical food preference analysis is critically discussed in view of the heterogeneous spatial distribution of invertebrates observed. [ABSTRACT FROM AUTHOR]