Ligulosis

a disease of cyprinids. The causative agent is the larva, or plerocercoid, of the genus Ligula of the family Ligulidae. The sexually mature helminths parasitize the intestines of fish-eating birds. Enzootic ligulosis arises most often in stagnant waters, predominantly in reservoirs, ponds, and lakes of various zones in the USSR and neighboring countries. In the body cavity of fishes the plerocercoids reach a length of 100–150 cm or more. The abdomen of infected fishes becomes strongly distended and hard to the touch. The fish grow poorly, become thin, and swim on the surface of the water, becoming easy prey for fish-eating birds. Control measures include catching infected fish, reclamation, scaring off and shooting (on ponds) fish-eating birds, and breeding fish that are resistant to ligulosis. A fish infected with ligulosis does not present a danger to man and is edible.