Danionella cerebrum lives in rivers in parts of Myanmar. It has been used for laboratory research for many years, but only now it has been singled out as a separate species.

Scientists from Germany, USA and Switzerland have proved that the small transparent fish found in Myanmar belongs to a new species from the genus Danionella.

Due to the lack of the skullcap and the transparent body, the brain of the tiny crystal harlequin is visible in the living fish. 

It is noted that the genus of ray-finned fish Danionella from the cyprinid family is considered one of the smallest vertebrates in the world. 

The length of an adult is 10-12 millimeters, it has no scales, and the body and head are so transparent that a living brain is visible. 

Due to its simplistic anatomy, Danionella traditionally attracts the attention of scientists: the fish lacks a skull cap, so it serves as an ideal model for neurophysiological research. 

Due to the size and simplicity of morphology, the identification of independent species within the genus Danionella is problematic, but without this it is difficult to reconstruct its evolutionary history. 

Biologists, using a combination of classical taxonomic methods and molecular approaches, have shown that fish, long used in laboratory experiments around the world under the name Danionella translucida, is in fact a new, previously unknown species.