Ligula intestinalis

The belt strap worm or tapeworm ( ligula intestinalis ) is a Eucestoda to the ( real tapeworms ) belonging parasite whose second larval stage ( Plerocercoid ) in the body cavity of Fried fish, mostly Cyprinidae, live.

Life cycle

The eggs of the tapeworm can take the feces of waterfowl into the water. From them emerges the first larval stage ( Coracidium ), which is active in a passing floating small cancer ( Copepoda ) drilling itself. The crustacean is thus used the belt worm as first intermediate host and in it the second instar develops within a few days ( Procercoid ). If now the copepod by a fish - usually a Cyprinidae - eaten in the body cavity the third larval stage develops ( Plerocercoid ). The Plerocercoid can be very large and perhaps get through a whole fish life. Only when the fish is eaten by a definitive host ( birds such as gull, great blue heron or cormorant ), the parasite matures zoom in intestine of the host for the adult tapeworm. The bird lays the hermaphroditic parasite millions of eggs that are released through the faeces of birds. The cycle is closed and is then repeated.

Morphology of the Plerocercoids

The second larval stage of the strap worm can grow up to 20 cm in fish. Usually, tapeworms of three parts: the head, the emergence zone and the link chain. However, the belt is not broken worm, which is an important characteristic for the determination of this kind.

Pathogenicity

For the fish

Due to the extreme size of the parasite 's internal organs to be displaced. In addition, the belt tapeworm suppresses the gonad of the fish, cut the fish by energy and hormone levels affected. So the cestode reserves to develop enough space in the body cavity.

For the People

The belt tapeworm is harmless to humans. The parasite is killed from a temperature of 70 ° C. A boiled or fried fish is thus no transmission to humans dar. Even if a live tapeworm would come into the intestine of a people (over raw fish ), he would be safe and would die within a few hours, since man is an accidental host. The only proven in Europe tapeworm that is transmitted to humans, the fish tapeworm, Diphyllobothrium latum is.