What are the intermediate hosts for fluke worms?

What are the intermediate hosts for fluke worms?

• A. Snails
• B. Fish
• C. Mosquitoes
• D. Frogs

Answer: (A)

Trematodes rely on an aquatic snail as the first intermediate host. After eggs reach water, a miracidium infects a suitable snail and, inside the snail, undergoes asexual multiplication to produce many cercariae. These cercariae then leave the snail to continue the life cycle, often infecting a second intermediate host such as fish or crustaceans, or directly entering the definitive host. Because the crucial amplification and development occur in the snail, the snail is the quintessential intermediate host for flukes. Some species do use other animals as additional intermediate hosts, but the common pattern centers on snails as the key first intermediate host.

Trematodes rely on an aquatic snail as the first intermediate host. After eggs reach water, a miracidium infects a suitable snail and, inside the snail, undergoes asexual multiplication to produce many cercariae. These cercariae then leave the snail to continue the life cycle, often infecting a second intermediate host such as fish or crustaceans, or directly entering the definitive host. Because the crucial amplification and development occur in the snail, the snail is the quintessential intermediate host for flukes. Some species do use other animals as additional intermediate hosts, but the common pattern centers on snails as the key first intermediate host.