This study aims to investigate the importance of the serum factors present in the plasma of resistant Biomphalaria tenagophila
snails, when transferred to susceptible conspecific. Susceptible B. tenagophila
(CF) received plasma from resistant B. tenagophila
(Taim), and both were later infected with Schistosoma mansoni
. We noticed that the plasma transfer showed an increase on the resistance of susceptible snails of about 86% when compared to the non-immunized group (p < 0.001).