New insights on growth, feeding, and social interactions in tilapia (Oreochromis niloticus)

Growth data reported here have been obtained in a work aiming to analyze the determinism of differential growth between male and female of #Oreochromis niloticus#. Growth indices such as white muscle RNA/Protein and uptake of 14C-glycine by scales have been implemented and tested as predictors of short term individuel growth rate. A method of scale labelling based on the incorporation of Sr supplied by the diet during early stages has also been tested. Growth has been characterized through morphology analysis and muscle development. At early stages, growth of tilapia resulted in height growth associated with an important hyperplasic growth capacity of muscle. Structure of muscle at microscopic level and muscle contractile proteins composition seemed to be original in tilapia as compared to other teleost. Voluntary feeding behaviours have been characterized. Feeding activity was observed only during the light period and peak of activity were observed related either to a disappearance of social hierarchy (morning) or to a compensatory feeding activity after daily social interactions (evening). The effects of increasing feeding rate have been tested in different experimental facilities to obtain differential growth at short term scale (15 d) and long term scale (from first feeding to sexuel dimorphism). High feeding rate (above ad libitum) resulted in reduce growth individual variation.