The Secret Life of Blood Flukes

Blood flukes are tiny worms that have found a creative, complicated way of reproducing themselves. It's so bizarre that horror-movie audiences would sneer, "That could never happen in real life." Except that it does.

Here's what happens. Read it if you dare!

Our movie opens with Jaws-like music. But instead of the ocean, we see a freshwater lake or stream. Lurking in the water are the larvae of blood flukes. They swim and wait until...

...some unsuspecting person enters the water to swim or bathe. A few lucky blood fluke larvae collide with the unlucky person's skin. Then they burrow...

...inside the person's body, where the blood flukes find their way into a blood vessel. The worms surf along, causing havoc and growing into adults. Sooner or later...

...some of the adults mate. They lay eggs in the vessels supplying blood to the person's intestine or bladder. Then, when...

...the person urinates, the blood fluke eggs go along for the ride. Depending on the water system where the person lives, some eggs may wind up...

...back in a lake, stream, reservoir, or other body of water. There the eggs hatch, releasing worms...

...which are homeless-but not for long. Young blood flukes invade the bodies of freshwater snails. They hang out for a month or so, growing larger and stronger, until...

...it's time to leave the snail behind. So the blood fluke larvae hit the big time-the water, that is. The worms swim and wait. Sooner or later ...

...some unsuspecting person enters the water. And the cycle begins all over again....

Still interested in learning more? See an actual blood fluke and find more facts on the disease it causes: Schistosomiasis.