Heritable non-susceptibility in an allopatric host-parasite system: Biomphalaria glabrata (Mollusca)-Echinostoma caproni (platyhelminth Digenea).

We studied the heritability of adult nonsusceptibility/susceptibility in an allopatric host-parasite system, Biomphalaria glabrata (Brazil)-Echinostoma caproni (Egypt). In this system, the fitness of the infected host is substantially reduced because of castration. Mean frequencies of susceptibility among progeny of individual susceptible or nonsusceptible parents were compared, and heritabilities of susceptibility and nonsusceptibility were calculated under a quantitative genetic model. A Monte-Carlo simulation was used to assess the significance of the heritability estimates under the hypothesis of normal standard deviation. The results showed high heritability of both nonsusceptibility (0.56) and susceptibility (0.91).