Tapeworm

Tapeworms are thin, resembling a strip of tape, which is why they are called tapeworm.

This parasitic creatures spend the early part of their lives in grazing animals and the latter part of their lives, when they reach adulthood, in digestive tract of meat eaters. Tapeworms absorb partly digested food through their skin from their host.


The Taenia saginata, also known as the beef tapeworm, is the most common type of tapeworm in North America; the Taenia solium, or the pork tapeworm, infects millions in Latin America; and the Diphyllobothrium latum, or the fish tapeworm, along with the pork tapeworm, are the types that are prevalent in Asia.



The worm's head attaches to the intestine of the host. In some species, the head is dominated by tentacles, which are sometimes called sucking grooves, and function like suction cups. Other species have hooks and suckers that aid in attachment.

Tapeworms are hermaphrodites; they have both male and female reproductive systems in their bodies. Even though they are sexually hermaphroditic, self-fertilization is a rare phenomenon. In order to permit hybridization, cross-fertilization between two individuals is often practiced for reproduction.

Tapeworm eggs

Many tapeworms have a two-phase life cycle with two types of host. The adult tapeworm lives in the gut of a primate such as a human. Proglottids (successive segments which contain eggs, so they can reproduce independently) leave the body through the anus and fall onto the ground, where they may be eaten with grass by animals such as cows.



In the cow's body, the juvenile form migrates and establishes as a cyst in body tissues such as muscles, rather than the gut; they cause more damage to this host than the intestinal form to its host. The parasite completes its life cycle when the grass-eater is eaten by a compatible carnivore—possibly a human with a preference for raw meat—in whose gut the adult tapeworm establishes itself.

A tapeworm coming out from a dog

Why the fuss about tapeworm?
Well many of us do not know that tapeworm is among the longest animals in the animal kingdom. The rest of this entry is not for the faint of heart~

First look at this picture.


This is a rather interesting picture, showing the largest animals and plants in the world. The ugly little secret is item no. 10, the line in the middle of the picture just below the dinosaur and the snake.

Inside the blue whale on the top of the page standing next to an elephant, then again at the base of the giant Sequoia, you will find a man and a dog. They represent sizes that you know well to help you see how big these life forms are.

There’s a third man-and-dog just below item no. 10… which is the item that got my attention. Wells, that’s a tapeworm found inside a human being!

Could it be our intestines are so convoluted that an animal can wiggle inside us and grow and grow and grow and become as long as a dinosaur? Show this to an 8 year old and you’ve created a nightmare that will last for decades.



So far the longest tapeworm ever found in a human is Diphyllobothrium latum, at 40 feet long. That's around 13 meters longs. Our small intestine is only 7 meters long.. =.=

You will be horrified to learn the fact (if you are a whale) that Hexagonoporus, also a tapeworm, which grows inside whales, can grow to 100 feet (33 meters), the length of a dinosaur. @.@

Parasites are awesome.. And we thought humans conquered the world alone.


Malcolm
info:
http://www.buzzle.com/articles/human-tapeworm-intestinal-parasite-infection.html
http://www.npr.org/blogs/krulwich/2010/08/25/129422903/here-s-something-you-don-t-want-to-know
http://en.wikipedia.org/wiki/Cestoda