The unio habitat of Taedong River has been registered as a natural treasure.

Lots of unio live in both riversides of Taedong River in front of Pongdo-ri six kilometres northeast of Richon-ri, Sungho District, Pyongyang.

Various measures are being taken to make good conditions for the unio to spawn in the winter season.

The unio belong to the Unionidae.

Its shell is 11 centimeters in length, seven centimeters in height and six centimeters in width.

Its external shape is bulging, long and round and the shell is very thick and hard.

The unio, living on diatoms, green algae and others, fully grow up in three years and each spawns some 200,000 eggs in winter.

Being the unio feed and propagation site, the place of the river is being protected well as a natural treasure of the country.