Parasitic worms turn snails into 'zombies'

Worms flatten the green parasite in the snail, then control the host to crawl out to attract predatory birds.

Lin Ruian on August 9 stumbled upon a strange snail while walking on the hillside in Zhanghua District, Taiwan. The recorded scenes show that the animal has big, bulging eyes that look like two colorful flashing neon lights.

Life cycle of earthworm flat worms.(Photo: Animal Diversity).

According to biologists, the snail has been infected with a parasitic helminth, the scientific name Leucochloridium paradoxum , also known as the green cavity flatworm. They have the ability to control the host's motor neurons, turning the victim into a "zombie".

Green cavity worms enter the snail's digestive system at the larval stage and continue to grow to adulthood. Adult individuals then try to crawl into the snail's eyebrows (tentacles) and constantly wiggle, making the host look more prominent and more easily detected.

Not only that, this parasitic worm also controls the nervous system of snails, causing them to automatically crawl on high branches or open positions to attract predatory birds.

When the snail bird, L. paradoxum continues to parasitize in the new host's abdomen and lay eggs before dying. Worm eggs are then taken out according to the bird's waste route and hatched into larvae. The larvae find their way into the snail's digestive system to continue their life cycle.