The first-stage larva of a parasitic fluke. Miracidia hatch from eggs released into water with the host’s excreta. They have cilia and swim about until they reach a snail. The miracidia then bore into the snail’s soft tissues and there continue their development as sporocysts.
The ciliated free-swimming larva of a digenetic fluke. On emerging from an ovum, it penetrates a snail of a particular species and metamorphoses into a sporocyst.
The stage of the schistosome parasite that infests snails dwelling in freshwater environments.