Leucochloridium paradoxum in an amber snail

An amber snail infected with sporocysts of Leucochloridium paradoxum. These parasite larval colonies migrate to the snail’s tentacles, where they move to and fro in a pulsating manner. Together with the cross-banded colour pattern of the sporocyst, this mimics a caterpillar, to which insect-eating birds (the worm’s next host) are attracted. Filmed along the river Gein near Amsterdam, 18 August 2012.