[2] It is considered to have evolved in the cave environment for some two million years.

[3] Its former generic name derives from the Greek words phreasatos for spring, and ichthys for fish.

[4] This fish is the first animal discovered that does not adjust its biological clock with the light of the sun.

It has an unusual internal clock, which measures the passage of time with an extremely long period (up to 47 hours).

[5][6] Two other cavefish species are found in Somalia: the cyprinid Barbopsis devecchi and the catfish Uegitglanis zammaranoi.