The Asp has a long body and a wide mouth, which extends behind its eyes. Its upper jaw has a small depression into which the protruding lower jaw fits. It has a grey-blue back and silvery sides. Its dorsal fin is placed behind the imaginary vertical line projected from the base of the pelvic fins. Behind its pelvic fins it has a scale-covered keel.
The asp is a predatory fish, which inhabits the lower reaches of large rivers and sometimes also lives in oxbow lakes. It prefers upper water layers, where it feeds on small fish, which it often attacks noisily, sometimes even jumping out of the water. It also catches insects fallen onto the water surface. It spawns between April and June on the stony bed against the current. The fry at first cat plankton, small insect larvae, the fry of other fish, and later progress to a diet of small fish.
In Europe it inhabits rivers to the cast of the Elbe and those opening into the Baltic, Black and Caspian Seas. It is not found in France, Britain, Denmark, Switzerland, the Iberian peninsula or in the southern part of the Balkan peninsula. Its economic value grows proportionately as one moves eastwards through Europe, where it is also a favourite prey of anglers.
Maximum size and weight : 1.2 m, 14 kg.
Identifying characteristics: Upper jaw has depression into which slots protruding lower jaw. Large mouth reaches behind eyes. Scale-covered
Other freshwater fish similar like the asp with predatory instinct is the Oscar