Abstract
In the Vaccares lagoon (Rhône delta, Camargue, France), mullets of the species Liza ramada (Pisces, Teleostei) are parasitized by seven metazoan species, ectoparasites of gills : six Monogenea and one Copepoda. The spatial and temporal structures of this parasite community were analysed. The host migrates within this delta in the course of the seasons, and its parasites are potentially affected by the fluctuating environmental constraints. The crossed effects between the structure of the parasite infrapopulations and some environmental characteristics were studied with a co-inertia analysis. This study emphasizes the interactions between the populations structures and the environment, and their consequences on local biodiversity.