Host death: a necessary condition for the transmission of Aphalloides coelomicola Dollfus, Chabaud, and Golvan, 1957 (Digenea, Cryptogonimidae)?

Eggs of the trematode Aphalloides coelomicola were observed free in the abdominal cavity of Pomatoschistus microps from March 1993 to October 1995 (Pisces, Gobiidae) in the Vaccares lagoon (delta du Rhone, France). The eggs were contained in a fine membrane of parasitic origin as no immunological reaction of the fish was noted. The alternatively high prevalence of adults and low prevalence of free eggs, and vice versa, suggest that P. microps is both the second intermediate and final hosts of the trematode Aphalloides coelomicola and that the mechanism of transfer to the first intermediate host is through death of the definitive host.