The biotope of branchial ectoparasites of fishes : factors of variations in the pattern sea bass - monogeneans

Abstract

International audienceFor the analysis of functional structure of communities, the ecologists are obliged to extend their investigations to the heterogeneity of their environment and colonized biotopes. The gills of sea bass Dicentrarchus labrax serve as a biotope for several ectoparasites ; some aspects of the heterogeneity of this biotope were studied quantitatively. The models expressing the variations of number of branchial filaments, and branchial area that can be colonized by monogeneans, were established in function of the lenght of fishes. Such biotopes being subjected to significant physical modifications, the effects of the latter over the organization of parasitic settlements are then discussed