Animal profile

Candiru

Vandellia cirrhosa

ActinopterygiiTurbid Amazonian rivers, generally within or near the substrate

Field profile

The candiru is a small, translucent parasitic catfish, usually only a few centimetres long, that feeds on blood from the gill chambers of larger fish. It is slender enough to be nearly invisible in turbid water.

Published field notes

2024-01-17

Candiru

The candiru does not track urine to a swimmer

The candiru's reputation rests on a claim that it follows a urine stream into the human urethra. Controlled tests found no attraction to urine or ammonia, and the fish appear to locate their host fish by sight rather than by chemical cue.

Read with evidence →