Zombie snails are something that until recently I had only seen on TV, but as luck would have it I actually came across one for real in 2016. A
zombie snail is actually an Amber snail (Succinea putris) parasitized by Leucochloridium spp. The snail eats the eggs of the flatworm and the larvae
develop filling the eye stalks making them look like wriggling caterpillars, often the snails will be much more out in the open than uninfected ones,
attracting bird which the parasite needs for the next stage of its life cycle.
The worm in its larval, miracidia stage, travels into the digestive system of a snail to develop into the next stage, sporocyst. The sporocyst grows
into long tubes to form swollen “broodsacs” filled with tens to hundreds of cercariae. These broodsacs invade the snail’s tentacles causing a brilliant
transformation of the tentacles into a swollen, pulsating, colourful display that mimics the appearance of a caterpillar or grub. Infected snails are
often called zombie snails.
Amber snail (Succinea putris) parasitised by a Leucochloridium sp.