This is the first larval stage in any digenetic trematode life cycle. This miracidium of
Schistosoma mansoni is
short-lived (24 hours), non-feeding, and seeks out a specific snail of the genus Biomphalaria spp.
It is ciliated with the anterior end to the right. The blue mass toward
the anterior end is a collection of penetration glands which release enzymes
that digest a pathway into the specific host snail. The larger mass toward
the posterior end is the germ ball which carries the germ line for the
polyembryonic development typical of trematodes. 400x