Broad Fish Tapeworm

(Diphyllobothrium latum), also known as the common fish tapeworm, an invertebrate of the class Cestoda, which parasitizes the human intestine and the intestines of some domestic and wild mammals. It measures up to 9 m long (sometimes up to 20 m) and 1–1.5 cm wide. The body consists of several thousand segments, or proglottids, each containing male and female organs. The broad fish tapeworm has a life-span of up to 29 years and sheds up to 2.1 million eggs per day. The life cycle includes two intermediate hosts, first a cope-pod (Cyclops, Diatoma) and then a predatory fish (pike, burbot, perch). The definitive host may be man, dogs, cats, or wild predatory mammals. Broad fish tapeworms are distributed predominantly along freshwater shores. In the USSR they are found in Karelia and the Baltic Region. These tapeworms cause diphyllobothriasis in man.