No Peeing In The Pool

So I read an article about this guy, a gentleman who already has swum the length of the Mississippi and the Yangtze Rivers, and is now attempting to swim the length of the Amazon, 3,745 miles in 70 days.
Apparently swimming in the Amazon has its share of dangers, including alligators, snakes, piranhas, and a continuous tidal surge where the outgoing river meets the incoming Atlantic that could drown you instantly. Swimming during the day avoids most alligators and snakes, and the boats that will accompany him downstream will be equipped with buckets of blood and chum to distract the pirhanas. However, these dangers seem like child's play compared to a fish I had never heard of, the candiru.
Here's a picture of the fella, apparently in the same family as a catfish.











The fun thing about the candiru is that they are parasitic, feeding on the blood of other fishes. However, humans are a tasty target as well, according to this Wikipedia article, parts of which are reproduced below:

The candiru...is attracted to (human) urine or blood...and will swim into an orifice (candiru are small, any orifice will do)...(Once well inside) it then erects its spine (to anchor itself) and begins to feed on the blood and body tissue...The candiru is then almost impossible to remove without surgery. Most often infection causes shock and death in the victim before it can be removed.

Huzzah for nature. I hope you enjoy the enlightenment.