[Ecological research work about Trematodes life-cycles in a Provencal lagoon (France). II. The cycle of Maritrema misenensis (A. Palombi, 1940) (Microphallidae Travassos, 1920)].

The authors point out the ecological conditions required for the life-cycle development of Maritrema misenensis (A. Palombi, 1940). This Microphallid parasite occurs in waveless lagoons as well as along the waved marine coast. The first and second intermediate hosts found in these two habitats are not alike. Along the calm edges of the lagoon edges Cerithium mediterraneum (first host) and Orchestia mediterranea (second host) are found whereas along the rocky sea-coast C. rupestre (first host) and O. montagui (second host) are to be seen. The first intermediate hosts are heavily infected along the margin of the lagoon; the parasitism is decreasing gradually as we go away the edge. The infection of the second host depends on the behaviour both of Orchestia and cercariae. Numerous cercariae accumulate against along the very edge of the lagoon, exactly where Orchestia enter the sea-water. The Orchestia parasitism varies as you go along the coast and according to the seasons; it is also different whether you are dealing with males or females.