A freakishly scary Amazon parasite

I'm reading "The Lost City of Z" by David Grann.  While buying gear for his trip to the Amazon, Grann chats with a store worker about the candiru.  I had never heard of this thing, but just reading the little bit that was offered just proved it was frightening.

Here's a picture of the thing:

Note how small it is.  Now, let's talk about what it eats: blood.  It lives on a diet solely of blood.  It usually feeds by embedding in the gills of fish, but when an unsuspecting human wanders into the river, well, it can enter orifices.  They're all bad, but the worst seems to be the male urethra.  Without immediate removal, some men from remote Amazon tribes have had their penises cut off in an effort to save them from what would be an inevitable death.

Many myths exist about these creatures so more lurid stories should be read with caution.  However, these parasitic freshwater catfish, which are indigenous to the Amazon river, are to be respected and feared.  Some would say even more so than the piranhas.