fish tapeworm

flatworm

Also known as: Dibothriocephalus latus, Diphyllobothrium latum(Show More)

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Last updated

June 26, 2026

Quick Summary

The fish tapeworm, Dibothriocephalus latus, is a type of parasitic flatworm belonging to the class Cestoda. These worms, found worldwide, can range from about 1 mm to over 15 meters in length. Fish tapeworms infect humans and other mammals that consume raw or undercooked fish, particularly in the Northern Hemisphere.1

The life cycle involves fertilized eggs passing from the host in feces, developing into larvae in water, and being ingested by crustaceans. Fish then eat the crustaceans, and the larvae encyst in the fish's muscle tissue. When a mammal eats the infected fish, the larva attaches to the intestine and matures into an adult tapeworm. Unlike other tapeworms, the fish tapeworm can cause a severe anemia similar to pernicious anemia because it consumes a significant amount of the host's vitamin B12.12

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digestive system disease
Tapeworms
Diphyllobothrium latum, a fish tapeworm, may cause a severe anemia similar to pernicious anemia, because it consumes most of the vitamin B₁₂ in the diet of the host.
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Diphyllobothrium latum, a fish tapeworm, may cause a severe anemia similar to pernicious anemia, because it consumes most of the vitamin B₁₂ in the diet of the host.
Read More

cestodiasis
…to 3 metres long; and Diphyllobothrium latum, or fish tapeworm, about 9 metres long—the largest parasite that can infect humans—acquired by eating undercooked beef, pork, or fish that harbour larval forms of the worms.
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…to 3 metres long; and Diphyllobothrium latum, or fish tapeworm, about 9 metres long—the largest parasite that can infect humans—acquired by eating undercooked beef, pork, or fish that harbour larval forms of the worms.
Read More

tapeworm
The fish tapeworm (Dibothriocephalus latus, or Diphyllobothrium latum), most common in waters of the Northern Hemisphere, infests humans and other mammals that eat fish, particularly bears and dogs. Fertilized eggs pass from the host’s body in the feces. In a water medium they develop into a…
Read More
The fish tapeworm (Dibothriocephalus latus, or Diphyllobothrium latum), most common in waters of the Northern Hemisphere, infests humans and other mammals that eat fish, particularly bears and dogs. Fertilized eggs pass from the host’s body in the feces. In a water medium they develop into a…
Read More