The sturgeon is a large fish, can achieve more than 2 m in length, with longevities that can exceed forty years. It has an elongated body with a prominent snout and a mouth in a ventral position, with four sensory barbels. Heterocerca tail and several rows of bony shields on the body.

It was distributed along the great rivers of Europe, both on the Atlantic Ocean side and in the Mediterranean and Black Sea, but at present only a small population remains on the lower course of the river Garonne. In Catalonia it was abundant on the river Ebro until the construction of the Xerta dam in the 15th century, which hindered their reproductive migrations. Despite this, remained in low numbers until the decade of 1960, when the last specimens were observed. Actualment es considera extint a Catalunya.

It is an anadromous migratory species, that goes up the rivers to reproduce. Juveniles move to river mouths, where after a year or two they migrate to the sea. Feed on insect larvae, crustaceans, mollusks and small fish.

The sturgeon is a critically endangered species in the world. Various LIFE projects with captive breeding programs are being carried out in Europe.