A digeneid trematode from a snail host (Nassarius) . Causes cercarial dermatitis in humans.. Microscope image shows cercariae being squeezed out of a redia.
The snail's infested viscera are shown in a macro photo as well. The snail was anesthetized before shell removal/dissection.
Spotted in South Harbour at the Poor Knights Islands, NZ. In a depth of 5-6m.