The presence of uninfected Omphiscola glabra in a breeding of infected Galba truncatula enhanced the characteristics of snail infections with Fasciola hepatica.

Experimental infections of Galba truncatula with Fasciola hepatica were carried out under laboratory conditions to determine if the presence of another lymnaeid, Omphiscola glabra, during snail breeding had an indirect effect on the growth of G. truncatula and to analyse consequences on cercarial production. When the two lymnaeids are raised together, the survival of G. truncatula at day 30 post-exposure (PE), the prevalence of snail infections, and the shell height of cercariae-shedding snails at day 45 PE were significantly higher. By contrast, the other parameters characterizing snail infections only showed insignificant variations. The origin of O. glabra (living in a snail community, or monospecific population) used for the breeding of G. truncatula did not have a significant effect on the values of each parameter. Even if variations in the mean numbers of metacercariae were insignificant, the greater survival of G. truncatula at day 30 PE and the higher numbers of cercariae-shedding snails in the groups living with O. glabra allowed to obtain a higher total number of larvae than in alone-raised groups of G. truncatula.