Pero vamos a ver, como quereis que remonte el flujo de la orina??? eso es físicamente del todo imposible.
La próxima vez que vayas a mear te paras a pensarlo y verás, la fuerza de la gravedad, la irregularidad del chorro... vamos, ni de coña.
En la wikipedia:
La única posibilidad que tiene de entrar es que estés debajo del agua, igual que la ameba.A well-circulated myth is that the candirú is capable of swimming up the stream of urine in mid-air to a victim standing on shore or a boat. This is physically impossible as the maximum swimming velocity of the fish is opposed by the downward velocity of the urine stream, and the further impossible act of the 5-14 mm wide fish maintaining position and thrust within a 2–7 mm wide column of fluid. They are also probably not attracted to urine as commonly thought.