Silvio Barbossa... was swimming in the Amazon River when he went head to head with the tiny parasite:
"I felt like urinating. I stood up, and it was then it attacked me. The candirú attacked me. […] When I saw it, I was terrified. I grabbed it quickly so it couldn't go deeper inside. I could only see the end of its tail flapping. I tried to grab it, but it slipped away from me and went in. […] I was very afraid, because the candirú bites."

When the candirú successfully invades a human, it proceeds exactly as it would with a fish host. After entering the misidentified orifice, it quickly wriggles its way in as far as possible, often accompanied by the victim's frantic attempts to grip the slippery, mucus-coated tail. In the unlikely event that the panicked victim manages to grasp the fish, its backwards-pointing barbs would cause excruciating pain at each pull, and bring a quick end to the dramatic tug-of-war. Once inside, the parasite inches its way up the urethra to the nearest blood-gorged membrane, extends its spines into the surrounding tissue, and starts feasting.

Man, I wish the piranhas had gotten him.

He said he was lucky to have escaped encounters with piranhas, the dreaded toothpick fish, which swims into body orifices to suck blood, and even bull sharks that swim in shallow waters and can live for a while in fresh water.

Just like they almost got me...

Clearly 'you are being attacked by flesh eating fish, you are terrified' was outside Bob's range.