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 lamprey
The Caspian lamprey is a slim-bodied, eel-like fish that grows to a length of about . The longest recorded specimen was long and weighed . Like other lampreys, it has no jaws, but it has a round oral disc surrounding the mouth. Inside this it has several radiating rows of tiny, backward-facing teeth. There is a single nostril near the eyes. There are no gill covers and the seven gill openings are visible just behind the head. The fish has no scales or paired fins, but has two elongated dorsal fins, the hindmost of which nearly joins onto the small tail fin. The Caspian lamprey is a silvery-grey colour.