Tapeworm Life Cycle

Tapeworms are parasitic flatworms that fall under the class Cestoda and Phylum Platyhelminthes. They comprise approximately 5000 different species of invertebrates that measure from 1mm to 15 m in size. Tapeworms are internal parasites that attack vertebrates like human beings, cats, dogs and fish. The disease caused by tapeworm is known as cestodiasis. Physically the tapeworm has an elongated body segment, head and suckers or hooks for attaching themselves to the host. Tapeworm bodies are covered with hard cuticle covering, through which they absorb food.

Let’s look at the life cycle of tapeworms to better understand.

Life Cycle of Tapeworm:

Majority of tapeworms are hermaphrodite. A hermaphrodite is an organism with both male and female reproductive organs. They produce gametes of both male and female sexes.

1) The Egg – Stage 1 –

Tapeworm eggs are usually released through gravid proglottids and can survive for days in the environment. Animals like cattle or pigs become infected by tapeworms when they consume vegetation.

2) The Larvae – Stage 2 –

The larvae tapeworm attaches itself to the intestinal walls of the host. The hatched larvae migrate to the striated muscles of the intestine. Here, they develop into cysticerci. Cysticerci can survive inside the host for several years. Human beings get infected with this cysticerci by consuming raw or undercooked meat.

3) The Adult – Stage 3 –

Inside the human intestine, the cysticerci develop for about 2 months and transform into an adult tapeworm. Scolex is the anterior end of a tapeworm that has suckers and hooks for attaching purposes. The adult tapeworm produces proglottids that mature, become gravid, eventually detach and migrate to the anus or pass in the stool.

Conclusion:

Tapeworms are named after their intermediate hosts, such as Diphyllobothrium latum (fish tapeworm), Taenia saginata (beef tapeworm) and Taenia solium (pork tapeworm). These are all intermediate tapeworms as they are consumed by other carnivores like human beings.