Schistosoma bovis: Variability of cercarial production as related to the snail hosts: Bulinus truncatus, B. wrighti and Planorbarius metidjensis

Development of Schistosoma bovis from Spain in different species or genus of intermediate hosts (Bulinus truncatus, B. wrighti and Planorbarius metidjensis) modifies cercarial productivity and its dynamics. From B. truncatus to B. wrighti and to P. metidjensis, cercarial productivity decreases while the length of the production period is increased. Variations in the dynamics are less obvious between the two species of Bulinus than between Bulinus spp. and P. metidjensis. In the latter the emission pattern is characterized by a 45–48-day production rhythm. These differences are explained in terms of larval demographic strategies and biotic capacities of the hosts. The validity of employing cercarial production as an indicator of host-parasite compatibility is discussed.