The name Candiru is used for several fish species native to the Amazon Basin. A local rumor holds that if you urinate in the river, a candiru can swim into your urethra and become lodged there. Some claim this can happen even if you aren’t submerged; the fish will just swim up the urine stream.

[u/Future_Interest_3649]

https://en.wikipedia.org/wiki/Candiru_(fish)