| Phreatichthys andruzzii | |
|---|---|
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Actinopterygii |
| Order: | Cypriniformes |
| Family: | Cyprinidae |
| Genus: | Phreatichthys Vinciguerra, 1924 |
| Species: | P. andruzzii |
| Binomial name | |
| Phreatichthys andruzzii Vinciguerra, 1924 |
|
Phreatichthys andruzzii is a species of ray-finned fish in the Cyprinidae family. It is the only species of the genus Phreatichthys, and is endemic to Somalia.
It is the first animal discovered who does not adjust its clock with the light of the Sun. This fish has an unusual biological clock, which measures the passage of time with an extremely long period (up to 47 hours), and is completely blind to all light stimuli.