Copyright information:Taken from "Gene expression patterns during adaptation of a helminth parasite to different environmental niches"Genome Biology 2007;8(4):R65-R65.Published online 24 Apr 2007PMCID:PMC1896014. Infective cercariae swim in fresh water to find and infect a mammalian host. After host invasion, cercariae transform into schistosomula and adapt to survival in the host bloodstream. The schistosomula mature into adult male or female schistosomes , which pair and produce eggs . Eggs are excreted from the host. In fresh water, the eggs hatch into miracidia , which infect a snail host and develop into sporocysts . Daughter sporocysts generate infectious cercariae, completing the life cycle.