PROTOZOAN AND METAZOAN PARASITES OF THE E EL ANGUILLA-ANGUILLA L, 1758 - TEMPORAL STRUCTURES OF THEIR POPULATION IN A MEDITERRANEAN LAGOON

Three parasite species, Anguillicola crassus (Nematoda), Myxidium giar di (Myxozoa) and Eimeria anguillae (Sporozoa) were recorded in the eel , Anguilla anguilla from the Mediterranean Lagoon of Mauguio (Southern France). A. crassus is found in the swim bladder, M. giardi in the ki dney and E. anguillae in the intestinal cells of this bony fish. A com parative study of the temporal variations in the population structures of these three endoparasites has been undertaken. This study reveals : a) the regular presence of these endoparasites throughout the year i n the eel, and the relative stability of intensities; b) the changes i n prevalence are rather cyclin in A. crassus; they increase during spr ing and autumn. This biannual prevalence change could be related to it s biological cycle and this later related to the planktonic blooms in these lagoons; c) the populations of M. giardi increase slightly durin g spring and autumn. Their periodicity however is less evident; d) E. anguillae is a regular species but does not present any evident cyclic features. The ecopathological consequences of these demographic chara cteristics are discussed.