h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

... there's also a certain kind of fish, a very small one with spiny fins. When you take a pee in an Australian lake, preferably in the bush, the fish will swim upstream through you urine stream, and using it's spiny fins, it lodges itself fast inside your urine tract.

Very dangerous to any man on the go... but also very non-existent

I've heard that this fish exists - but not in Australia. It lives in the Amazon river.

Maybe I've just heard a different version of the same myth...

Yes or possibly Africa, I seem to remember some jungle explorer discussing it on some chat show in my youth (possibly Wogan or Harty)
Definitely not Oz

These fish really do exist, I don't know if in Australia however, and there are also small worms that do something similiar that call the south pacific and south eastern asia home. The worm that has a tendency to swim up the urethrea of an unsuspecting victim was the cause of what many Vietnam vets thought was a strange STD that caused the penis to turn blue, to purple, then to black in the course of a week and would then fall off as it would feed upon the large blood vessels in the poor soldiers manhood. God I hate jungles, no offense to any jungle dwellers out there.

:[ thats very disturbing.... glad im not a guy

but how can it swim up the urine stream??

wat about gravity?

This is known as the Candiru (sic) fish and does indeed live in the Amazon basin.

They get you when you're swimming, so don't pee in the pool... err, river.