Environment of Azerbaijan
The Caspian Sea is the largest lake on Earth by both area and volume, with a surface area of 371,000 square kilometres (143,244 mi²) and a volume of 78,200 cubic kilometres (18,761 mi³). It is a landlocked endorheic body of water and lies between Asia and Europe. It has a maximum depth of about . It is called a sea because when the Romans discovered it they tasted the water and found it to be salty. It has a salinity of approximately 1.2 percent, about a third the salinity of sea water.
Caspian gudgeon
The Caspian gudgeon ("Gobio holurus") is a freshwater fish species in the family Cyprinidae. It is a small fish, less than 10 cm, which is distributed in the drainages of the Western Caspian Sea basin (Kuma, Terek and Sulak river drainages) in Russia and adjacent countries. It is widespread and not threatened, but there is no information about its biology.